The eucalyptus can be found in a variety of sizes with some species being among the largest trees in the world; whereas, other members of the genus, may be mere shrubs. It grows on the desert, swampland, valleys, and alpine regions. It finds nourishment in a complexity of soils and can survive in differing types of climate.
The eucalyptus is an evergreen and many species grow very rapidly especially globulus. Mostly erect in form, the tree is strong and usually slender. It is an aggressive plant whose leaves demand every vestige of sunlight, and its roots suck up all the moisture within their domain. The color of the wood varies from white to dark brown depending upon the species with the heartwood and sapwood being indistinguishable among species. The grain of this hardwood is similar to hickory or ash and is just as beautiful if handled correctly by the workworker.124
It propagates best from seed, and because of this, there is no transfer of disease as would be the case with cuttings or seedlings.125 This has been an important factor in the success of eucalyptus in California which has been virtually disease-free; thus, from the beginning of its introduction into California, eucalyptus seed and not seedlings have been imported from Australia.
Of all the Australian plants, the eucalyptus species are the most difficult to distinguish from one another because of their physical similarity.126 The eucalyptus belongs to the Myrtaceae family in which there are ninety separate genera. In the eucalyptus genus there are over 600 species, and even this figure is an estimate, because there are numerous separate varieties that have a similar nomenclature. This is because trees within an eucalyptus grove grow closely to each other, producing many hybrids.127
Classification of the various species of the eucalyptus was first attempted in 1789 by M. Willdenow who used the shape of the operculum or lid as his basis. In 1828 Augustin Pyramus de Candolle created another classification which was based on the leaf's relative position to the stem. Von Mueller designed still another classification which was contained six bark types. In 1886, George Bentham, followed still with another based on the anthers, which is where the pollen is found, and modified by fruit types and types of oil found on the leaves.128
The idea behind formulating a classification is to simplify the identification of the species. But as one can see, classification is in the eye of the beholder -- basically how the inquiring scientist sees the plant. Because of advances in science and technology, identification has been made easier, and because of this, new species have been found. Other eucalyptus classification systems have been designed besides the ones noted above, but the method of using the operculum as a basis seems to be the standard.
For most eucalyptus species mild climate is the best where there are warm summers, temperate winters, moderate rainfall, dry atmosphere, and plenty of sunlight. Temperature tolerance ranges generally between 15 to 100 degrees F. Quick changes in temperatures, however, are stressful for the eucalyptus especially in the weaker trees. Occasional storms with heavy rainfall are better than frequent rain because sunlight is important for growth as well as moisture.129
The eucalyptus grows best along the coast of central and southern California which is substantiated by observing the lush healthy groves and forests found in those areas. An outline of the eucalyptus growing region can be seen be locating the frostline on a California map. Frost-tolerance varies from species to species. For example, blue and sugar gums are damaged when temperatures dip below 26 degrees F. while manna and gray gum can withstand colder temperatures to 22 degrees F. Seedlings many times are killed by extremes in temperatures because of their small size and fragile nature.130 Humidity is important to some species especially the blue gum which does quite well in coastal fogs.131 As a rule of thumb, most eucalyptus species will be successful wherever citrus and olive trees are successful as they essentially require the same climatic mix of moisture and warmth.132
Drought in recent years has made Californians more conscience of water conservation especially in regard to plant life. Some eucalyptus species have proven to be drought resistant. In the 1917, there was a drought in California where temperatures hovered between 110 and 120 degrees F. It was found that the foliage on most eucalyptus trees burned with the amount of tree damage being dependent upon type of soil and wind. Trees in loamy soil did better than those on sandy soil because it contained more moisture. A survey was done concerning the number of trees killed by the 1917 drought. It was found that of 2,885 blue gum trees examined only 9 died. The red gum did even better in that only 10 trees died out of 4,461.133
The amount of frost an eucalyptus tree can take is determined by the atmosphere's humidity, the tree's condition, the tree's sap flow, and the age of the tree. Older trees can take temperatures up to 15 degrees F.; whereas, younger trees can take only a minimum of 24 degrees F.134 The covering of young trees with straw or gunnysacks is important to protect them from the cold. Exposure to sunlight at any point, young or old, is important to a tree's survival especially in colder weather. Of all the eucalyptus species amygdalina (peppermint) has proven to be the most resistant to frost.135 This is followed in frost-tolerance order by red, gray, manna, blue, sugar, and lemon gum trees.136 To develop a grove of frost-tolerant eucalyptus, collect and plant seed only from those trees that give evidence of resistance to frost.137
A freeze hit southern California in 1913 where temperatures dropped to 14 degrees F. It was found that not a blue gum was lost, and trees in dense groves suffered the least because colder temperatures were kept away from the inner trees. Blue gum resprouted the quickest to replace the foliage that had been damaged. Plantations having one or two year old trees lost 85% of them. Manna gum proved to be the most resistant to the cold with only 20% of its foliage being damaged.138 E.N. Munns, Forest Examiner of the U.S. Forest Service, studied the damage and published his results in Journal of Forestry. It is an in-depth study of the species and their damage with the most popular species having good survival rates.139
In December 1932, temperatures in the Central Valley dropped to 5 degrees F. Many eucalyptus trees looked destroyed, but because the roots were still alive, foliage resprouted as warmer weather came forth in the spring. Cold winter weather is not uncommon in California because the Alaska storm system sweeps the region. The 1972 freeze did burn back many species of eucalyptus. Once the litter was cleaned from that freeze, another cold-snap hit in 1990.140 The species less affected by frost are the ones which grow the slowest. They contain less water and hence less moisture to freeze. But it is the common thought, that since eucalyptus resprout anyway after environmental damage, it is still profitable to plant the faster growing species.141
Recent studies and reports have been published in regard to environmental tolerance of eucalyptus. New hybrids and clones are being tried with the hope of finding species that will resist satisfactorily radical temperature fluctuations.142 A report on frost damage from the 1990 freeze identified certain factors that determine eucalyptus damage among which are soil moisture content, duration of the low temperatures, tree size and condition, local climate, and the time in the season the freeze strikes. In the 1990 freeze, temperatures went as low as 10 degrees F. in the Bay Area. The eucalyptus trees suffered enormous amount of damage from curled stems and twigs to split bark.143 It is a fact of life, that freezing weather is unkind to this genus, but it is also true that it will fight back by producing new sprouts in the warmer months. It is simply a hard tree to kill.
The perfect soil for most eucalyptus species is deep, well-drained loamy soil. The problem is this soil is used by other more valuable agricultural crops. The eucalyptus is generally planted on unused or worthless sections of acreage which contain poorer soil. The chemical composition of the soil is important though in that large amounts of harsh chemicals will stunt and damage the tree.144 The soils moisture content too is important because most eucalyptus species are dependent upon massive amounts of water for their quick growth.145
Water availability depends upon the water table depth. Ideal depth for most eucalyptus is a water table that is eight to ten feet below the surface. Some species do well with a water table depth at thirty feet. Hardpan near the soil surface is not good though because the roots are prevented from seeking the water table. The roots will in this case grow laterally not giving the tree a strong and sturdy taproot. Eucalyptus responds well to moist soil through natural rainfall or irrigation. However, most species won't grow in standing water such as is found in swampy land. Two species which do excel in such dampness are the red gum and swampy mahogany.146
Soils for eucalyptus need to contain plant food elements such as potash, lime, magnesia, iron, phosphoric acid, and humus with high nitrogen content.147 Eucalyptus roots can spread out to 100 feet laterally and sink 60 feet into the soil.148 There has been much experimentation with eucalyptus growing in alkali soils. Alkali deposits can stunt a tree's growth until the roots break through it.149 But there are species that can absorb alkali removing it from the soil so other crops can be planted successfully. In 1985, over 650,000 eucalyptus and casurina trees were planted in western San Joaquin Valley to determine the ability of these genera to remove alkali found in the soil of undrained land.150
Eucalyptus seeds are generally small in size with only a few within
a capsule being fertile. The hardiness of the tree determines the number
of seeds it produces. Trees between twenty to forty years of age produce
the most seeds. Sunlight is needed to germinate seeds that is why in dense
forests or groves no seedlings grow. The canopy of the foliage and the
litter on the ground keep the sunlight out.151 But when a fire sweeps through
a forest, seeds are exposed to sunlight allowing replacement of damaged
trees. The eucalyptus produces massive amounts of seed to allow survival
after such environmental damage.152
Many non-native plants do not reproduce from seed naturally, but eucalyptus do in California.153 This demonstrates its adaptability to foreign climate and soils. The fruit of the eucalyptus remains unopened until it falls to the ground. Seed dissemination is uncommon by the wind or birds; consequently, seedlings appear right beneath the parent tree where the fruit dropped.154
In the early planting years in California, results from eucalyptus seed held some surprises. Quite often the species desired was not the species produced from the acquired seed. This caused much discouragement and frustration. Even seed from known experts were mistakenly identified. For example, Baron von Mueller sent seed to L. Stengel, a Los Angeles nurseryman, which produce other species than thought. The problem was not really in the mishandling and misidentifying seed, but lay in environmental differences. Because California varies somewhat in climate and soil from Australia, the Australian seed planted produced a California eucalyptus which is somewhat different in char- acter.155 Also, many eucalyptus look alike such as the manna and red gums.156
Abbot Kinney remarked in 1895 on seed confusion: " One of my most reliable correspondents in years gone by has sent me seed marked Eucalyptus polyanthema, which turned out to be Eucalyptus gunnii, and packages of rostrata that in one case contained six different species of Eucalyptus."157
Blue gum seeds are small, mostly fertile, and can be kept for up to four years before planting. One ounce of seed contains 10,000 fertile seeds.158 Still eucalyptus trees can be difficult to propagate due to the smallness of the seed, general infertility, and required climates.159 The best time to collect seed is in late summer or early fall. Spread the seed capsules out in the sun and the seeds will be expelled from the capsules in a few days. Good seeds will germinate within a week.160 Start the young seedlings with seeds in flat nursery boxes. Plant the seedlings in prepared soil after the frosty season. It is best to plant on cloudy days with the likelihood of slight rain.161
In recent years, seed sources have become extremely important because of the economics of the massive eucalyptus plantations found in Brazil and China. In 1985, the first seed source studies began to appear where seeds gathered from various locations in Australia and California were tested for hardiness and growth.162 Of recent, there has been such a demand for seeds from the Lake Albacutya area, an Australian national park, to the point where the authorities are concerned that there is not enough seed left to maintain the natural forests there. This puts pressure on the non-Australian countries to grow their own seed for planting.163 In 1987, tests began to enlarge the pool of California-produced seed. Such studies are important because reliable seed sources are critical to the future of eucalyptus as a commercial entity.164
In place of seed reproduction cloning of eucalyptus is being tried. This is done by taking a "rooting" from a stem or stump, and planting it; thus, the new tree is in reality the same tree or a clone.165 Hybridization can occur though when several species are in a grove sharing the same soil. Selection of a rooting then must be done carefully to assure that the desired clone is produced.166
Young eucalyptus require frequent watering. Coastal trees usually find enough moisture from fog where the trees in the inland valleys get water from irrigation. Weeds need to be eliminated near young trees because they rob the soil of the life-sustaining nutrients. Also rodents need to be kept away from seedlings because they will ravish them.167
As the eucalyptus grows its lower branches drop off leaving a trunk that is like a straight pole. In crowded groves, young trees compete for sunlight making them
straight and thin.168
Hardness, strength, durability, and flexibility varies with each species. Eucalyptus is generally very tough, and resists denting, tension, and torsion.169 Strength tests done early this century found that eucalyptus compares with white oak and hickory. Australian and California grown eucalyptus were tested for strength and found that there wasn't any difference.170
Because eucalyptus uses extreme amounts of water to feed its fast growth, the woodgrains are few, and the texture is very dense. Freshly cut eucalyptus wood will sink in water because of its weight.171 After being dried, shrinkage of eucalyptus timber is between 34.6% and 13.5% depending upon the species and environmental conditions.172
The color found in eucalyptus foliage varies according to the species, and usually it is blue, light or grayish green, or dark green. The foliage varies in density from sparse to very dense. Young leaves are broad and short becoming long and narrow as the tree ages. The edges of the leaves point to the sun for the collecting of sunlight. Leaves are also thick and leathery containing oil glands which emit a highly-scented odor.173
In most eucalyptus species, the flowers are noticeable with some being profuse and showy. Their color varies from white, cream, pink, yellow, and red depending upon the species.174 There are two types of flowering eucalyptus: one which flowers once a year and one which flowers most of the year. Only sideroxylon and polyanthema species are of the former, and amygdalina, regnans, angostrifolia, and linearis are examples of the latter. The constant availability of pollen for honey bees year round is an economic advantage, but eucalyptus honey has a strong peppermint taste and odor which makes it disagreeable to some consumers. Manufacturers mix it with orange blossom honey for a better taste and scent.175
BARK, TRUNK, and ROOTS
Eucalyptus is known for its shedding bark and its smooth white, almost porcelain-appearing, surface underneath. Commonly today, along California freeways, one can see another type of eucalyptus which has a black furrowed surface that doesn't shed. It doesn't have the artistic appearance of the other but serves a purpose in the drought exposed areas of the interior.
Baron von Mueller developed a classification of eucalyptus by bark type. For example, gums have smooth bark which is gray-creme and sheds in ribbons or in flakes. Bloodwood species can be both smooth-barked or rough-barked. Boxes and peppermint species have fibrous and closely interlaced bark. Stringybarks are fibrous, thick, coarse, and don't shed. And ironbarks have black furrowed bark containing kino or resin which hardens in the air.176
The trunks of many eucalyptus species are erect and straight-grained. The circumference of these trunks is larger at the bottom gradually getting smaller going up the trunk. This is a proper shape necessary for poles, masts, and piles. There are some species that have crooked trunks and are used for other purposes.177 Some trunks look like mottled marble being silver or white in color.178 Eucalyptus trunk wood is as hard as hickory and just as tough to penetrate.179
The root system is important to the eucalyptus primarily because its rapid growth and size demands large quantities of water. It needs a strong taproot to secure it and lateral roots to support its size. The taproot needs to sink down into the soil at least six feet for good anchorage. Lateral roots will spread out to one hundred feet which can be a problem when planted near buildings and other types of facilities. The roots and rootlets can disrupt ditches, crack cisterns, clog water pipes and damage septic tanks.180 Eucalyptus roots are aggressive.
For survival the eucalyptus has a natural tendency to resprout after it has been cut back or environmentally damaged. Usually within three to six weeks new sprouts will appear. It is suggested to keep two to four of the largest and more erect sprouts while removing the others. This will give those remaining sprouts the opportunity of being satisfactorily nourished. These new sprouts in reality are new trees growing from a mature root system.181
The proper time for cutting eucalyptus for lumber and firewood is during the rainy season. This way there is enough soil moisture for the stumps to sprout vigorously. After groves have been recut several times, they decrease in rate of growth and yield. One should consider replanting when depreciation is readily noticable.182
Eucalyptus serves man well. It has more useful purposes than any other tree on earth. For example, it provides forest cover for any terrain from mountains to swamps. It gives shade and acts as a windbreak. It furnishes gum, resin, oil, and nectar. When cut it is used for fuel, construction, poles, posts, and hardwood products. The eucalyptus even has the reputation of improving the climate in which it grows.183 It has been proclaimed to be "The Tree of California."184
In its native land of Australia, the eucalyptus was found in virgin forests and provided the settler with a multitude of products from firewood to strong timbers. It was used in the manufacture of ships, bridges, railroad ties, railroad vehicles, wagons, furniture, agricultural implements, paving blocks, barrels, poles, piles, and posts.185 It was used just like hickory, oak, and ash in the United States.
It was found in Australia that blue gum wood used inside railroad cars
lasted at least twenty years. Such use requires elasticity, strength, and
durability. A house was
built in Toowoomba from eucalyptus and was still in excellent condition after thirty years. A bridge crossing the Dawson River containing eucalyptus girders and piles, forty years later was as strong as when first built.186 Eucalyptus wood can be as hard as iron and as durable if it receives proper treatment.
Eucalyptus has been used in place of mothballs, to scour out boilers, in various medicines, pulp for paper, and in landscaping. Today it is used also as biomass fuel, ply- wood, charcoal, and as an alcohol substitute in gasoline engines.187 It also is being used to drain waste water to eliminate soil salinity.188 (Even the Israelis have used eucalyptus trees surreptitiously to mark Syrian targets.189 In Mexico, marijuana and poppy growers have used eucalyptus to hide their illegal crops.)190 There are so many uses for eucalyptus that it is like the proverbial pig where everything is used except the oink. In the case of the eucalyptus, everything is used except the noise from its rattling leaves and someone might find a use for that with new technology.
AS FOREST COVER
Eucalyptus provides valuable forest cover which can become especially thick if not maintained properly. Ellwood Cooper was the first to recognize its potential as a forest cover and discussed it at some length in his lecture at Santa Barbara College in 1870. He planted eucalyptus on a massage scale at his Santa Barbara ranch,
beginning with 50,000 trees in 1872. He planted seedlings on hillsides, in canyons, on ocean bluffs, and flatlands. Cooper planted them not just for forest cover but for wind-breaks, shade for roads, for timber and firewood. In 1900, he had 200 acres of eucalyptus forest of various species which was a showcase to interested public. McClatchie wrote in Out West in 1904:
One can stroll through his groves as through primeval forests. In the canons, Eucalypts twenty-five years old tower high above oaks that have been growing there for over two centuries. On hillsides that were formerly bare are dense forests in which ferns and other shade-loving plants find a home. Wind-swept plains that formerly gave small returns in the crops to which they were planted yield abundantly since they have been sheltered by groves of Eucalypts. For over a score of years Mr. Cooper has been reaping the reward of his foresight. Besides enjoying the beauty, the shade, and the shelter of his grove, he has received from them directly a good financial return for his expenditure.191
AND BIOMASS FUEL
Using wood as fuel for heating and cooking is as old as man. Because of its rapid growth, eucalyptus became an attractive fuel and was planted for that reason and for that purpose. Today, besides the traditional fireplace or cookstove uses, eucalyptus wood is chipped and used as biomass fuel in the generation of electricity.192
It was suggested in a 1903 Scientific American article that because of its rapid growth and size, eucalyptus would replace other fuels such as coal in California. Fuels from petroleum were entering the mass market at this time and soon would replace most wood sources. Still most homes used wood for fuel and industry used wood in its steam engines.193
Wood from most eucalyptus species makes good fuel. Groves of five years will produce 50 to 60 cords while groves of ten years will supply 80 to 150 cords. The quality of the soil, irrigation practice, and maintenance will vary the size of the yield. The cost of cutting the grove is determined by the age of the tree and the type of species. In 1908, it took one-half of the market price to cut and stack wood for sale.194
For so many years in southern California, firewood came solely from blue gum trees. This area was virtually treeless and eucalyptus groves were planted to service the need. In 1908, this was said about the firewood industry.
The returns of investments in Eucalyptus plantations have been generous, in many cases exceeding those received from equal areas under cultivation in orchards or agricultural crops. Groves set out in fertile Los Angeles Valley have yielded from 50 to 80 cords per acre at every cutting. Yields of 75 cords per acre every seven or eight years have been frequent.195
In northern California, planting of eucalyptus for firewood before 1900 was not on a large scale because oak was still available. In 1910, it was predicted that oak would vanish as agriculture encroached, and consequently forests of eucalyptus would be needed.196
Eucalyptus burns brightly and has a refreshing fragrance. It is equal to oak as firewood and is better than other natural California wood. The best fuel comes from ten
year old trees.
It does cost more to saw and split wood from mature trees because of their size and hardness. In 1924, eucalyptus firewood garnered profits of $1.50 to $4 a cord varying according to the condition of the wood, location of the grove, and other contributing factors. On contract, grove owners had wood cut and stacked for $8 to $12 a cord. When sold to the customer in the field, a cord brought $10 to $16, but if delivered, a cord would bring $18 to $24. However, when competing with other wood, eucalyptus might bring as little as $1 a cord depending upon the distance from the market and the nature of the terrain.197
It was reported in 1908 that eucalyptus wood was sold in 96 cubic feet cords, known as the "California cord," rather than the usual standard cord of 128 cubic feet.
Logs were in ten inch lengths rather than the normal eighteen inch lengths and was bought by consumers without much protest.198
Because of its high water content, eucalyptus wood would shrink by 15% as is the case with blue gum when seasoned. Eucalyptus wood had to be split quickly after cutting because as it dried it became very tough. Straight-grained species, such as sugar and red gums, usually split without difficulty, but blue gum with its interlocking fibres had to be split immediately. Blue gum too could not be put directly on the ground as it rotted quickly.199
During the eucalyptus boom, an eucalyptus cutting industry developed in southern California. Groups of cutters would harvest blue gum on a contract basis. These traveling gangs of woodcutters would saw and split wood at $2 to $3 a cord. The growers would in turn sell the wood for $3 to $8 a cord price varying according to the amount of transportation needed to move the cut wood.200
Over the years the University of California, the U.S. Forest Service, and other governmental agencies have done numerous tests on eucalyptus comparing species and comparing eucalyptus to other trees such as oak and hickory. These tests were done to determine eucalyptus' value as a fuel and as timber resource. These tests continue today because of the interest in biomass fuel worldwide.
From 1977 to 1984, a growth rate study was done in northern California which found that the eucalyptus species viminalis and camaldulensis grew faster than Monterey pine, walnut, and redwood.201 Another study was taking place at the same time, analyzing the survival and growth characteristics of eucalyptus species. It was found that globulus, camaldensis, dalyrympleana, and clones of camaldulensis were the better species in a foothill environment when under an intensive maintenance program.202
The Simpson Timber Company, Tejon Ranch, the U.S. Bureau of Land Management, and U.S. Forest Service's Institute of Forest Genetics collectively ran tests at twelve eucalyptus groves in California concerning the eucalyptus' viability as a fuel for industrial plants. Another part of the study was on quality seed sources. The results were positive as indicated by this remark at Tejon Ranch: "We started growing eucalypts three years ago and so far it looks promising. If the trees are profitable, we'll grow them alongside our other cash crops."203 It was found that blue gums can produce ten tons of dried wood per acre per year. Such a yield comes from fifty foot eucalyptus trees that are about six to ten years old. This same yield would take other hardwoods nearly fifty or more years to produce."204
There are many misconceptions as to the quality of eucalyptus firewood. It is felt by some that it doesn't generate as much heat as oak and orchard trees. It is the moisture in the wood that determines heat value. The drier the wood the more heat value it has. Freshly cut wood generally has about 50% moisture content. When dried, moisture content is drops to 10% to 25%. Wood from most eucalyptus species generate heat equal to oak, but orchard wood being denser, generates more heat. But ultimately, it is the heating appliance (stove) that really decides the degree of heat produced anyway.205
The oil shortage of 1973 caused the government to look for alternative sources of energy. It has been suggested that hardwood could be grown on unused federal lands, and this would supply 5.6% of U.S. energy.206 In 1989, there were at least seventeen furnaces in the United States that burned wood or biomass wastes to generate electricity. Some generating stations have explored the possibility of growing their own trees near the stations for less costly harvesting process.207
In 1988, Cal-Bio, a biomass firm, had projected the construction of five biomass plants in California and felt that chipped eucalyptus wood could be used. It would take 150 to 200 tons of material each year to fulfill the need. But it was found in a recent study that the cost of harvesting, chipping, and transporting the woodchips would be too costly to justify the investment. One solution was to plant trees nearer the biomass plant and plant more acres.208
The estimation of the volume of fuel an eucalyptus tree produces has proven to be difficult to calculate with a great deal of accuracy. In 1974, the California Department of Forestry designed a table to project the yield from blue gum trees, but the table was for trees used as windbreaks and not grown specifically for fuel. In 1989, another table was developed to remedy the problem.209 It is not easy to predict yield because there are so many variables that can alter production, such as the age of the tree, spacing between trees, weather, soil, pests, and other environmental factors.210
The research now is centered on scientifically producing eucalyptus species either through genetics, cloning or seed selection. There is a growing body of scientific literature on the eucalyptus. Recently an eucalyptus organization was formed which is based in Davis, California. Its name is the Eucalyptus Improvement Association, and it publishes numerous studies, reports, a quarterly newsletter, and news of the industry. It is a nonprofit organization consisting of private landowners, farmers, state and federal agencies, university extension, and forest industry personnel.
In 1978, the U.S. Department of Energy published a study entitled, "The Eucalyptus Energy Farm." It is a marvelous document providing a wealth of information on running one's own energy farm successfully.
An eucalyptus workshop was held in Sacramento, June 14-16, 1983, under the sponsorship of the Pacific Southwest Forest and Range Experiment Station and the Cooperative Extension at the University of California, Berkeley. Speakers shared their knowledge of species selection, products, uses, economics, growth, yield, cultural requirements, breeding programs, and propagation.211
There is a continuing interest in finding new uses for the eucalyptus. At the MIE University of central Japan, for example, eucalyptus-produced fuel was used in a small farm engine. The fuel produced about the same power as gasoline but emitting 50% less carbon monocide. Cost is a factor because it takes $10 to produce a litre (1/5 of gallon) while it costs 60 cents to produce petro.212
Eucalyptus is also used to make potash and charcoal. Potash is made by burning wood in pits, leaching the ashes, and evaporating. But in the late 19th century, potassium compounds were found and replaced potash in the making of ceramics, glass, soap, fertilizers, and munitions.213 Eucalyptus produces an excellent grade of charcoal better than most native California wood. One cord of eucalyptus makes 1,000 lbs. of charcoal. To produce charcoal, wood is burned in a kiln for about three weeks. It must be watched constantly which makes it expensive to manufacture.214
Windbreaks are used to reduce the wind's force or velocity to make life more livable for humans, plants, and animals. It reduces soil erosion and limits dust. A home can save 30% of its heating and cooling costs by having a windbreak because it reduces the effect of hot and cold winds. It also provides shade. In regard to crop production, it reduces wind damage to crops thus yields are greater. Windbreaks protect stock improving their condition. Milk cows give more milk, and sheared sheep suffer less. Currently a windbreak could cost $1,500 to $2,000 but the results pay for it.215
Blue gum trees make the best windbreak. Some of the other species are too short or they don't have enough foliage to disrupt the wind. When planning a windbreak, it is important to know the wind patterns in the area and to select the proper species. In 1950, it was reported that there were two thousand miles of windbreaks in southern California primarily to protect citrus groves.216
Crop protection is vital in California as some agricultural crops would fail without the benefit of eucalyptus windbreaks. This commentary reveals that importance:
In citrus sections, such as the Santa Paula, San Fernando, San Bernardino, San Gabriel, and Santa Ana valley, windbreaks alone render the production of citrus fruits profitable. In unprotected orchards, nearly the entire crop is frequently blown from the trees, or so scarred and bruised that the grade and market value are much reduced. Orchard trees are even broken or partially defoliated during severe storms."217
Windbreak trees must be "wind-firm." The eucalyptus has an extensive lateral root system which makes it "wind-firm." Blue gum is a perfect windbreak tree because it has strong root anchorage, a flexible stem (trunk), and foliage that redirects wind. Its foliage does not stop the wind but directs it upward which is ideal for crop protection.218
In northern California, eucalyptus windbreaks are used to protect vineyards, nut and fruit trees, vegetables, and grain. As one has observed, "Eucalyptus windbreaks in some sections have changed the aspect of the country, and by moderating the winds have greatly improved climate. Waste and sandy stretches have been turned to productive agricultural use."219 In Oxnard, windbreaks hold in place loose sand which is usually buffeted by strong gusty winds. The sugar beet industry in Oxnard would be non-existent if it weren't for the windbreaks.220 In the Salinas Valley, windbreaks divert winds that could ruin truck farming crops.221
Eucalyptus windbreaks protect towns and seaports from damage. In the latter, docked vessels are left secure and unharmed by fierce winds that can hammer the sea
coast. Sand stays in place and does not drift. It is recommended that eucalyptus windbreaks run at right angles every quarter of mile on level ground. Near the foothills, the spacing should be closer together however. To protect orchards, the windbreak rows should have a space every 100 to 200 feet. Heavy winds will sway the upper foliage of a windbreak tree, but the bottom foliage shelters the crops. Windbreaks also help to protect against freezes by cutting back on windchill.222
The best spacing for individual trees within a windbreak is four feet in double rows. Double-row configuration is especially good where there are strong winds because it prevents wind leakage. Trees are planted in double rows in an alternating fashion sealing off the holes in the windbreak. It has been found that windbreaks on the north or east sides of an orchard or field is less affective. Usually the south side is left open for wind drainage. It is not uncommon to find where there are strong ocean breezes multiple rows of windbreak trees. Many windbreaks use a combination of Monterey pine and eucalyptus. One has density while the other has height.223
Eucalyptus windbreaks should be properly managed. Older trees should be removed because they lack lower foliage which will allow wind to get through. Litter dropped by the windbreak trees should be picked up to protect against fires which can destroy a windbreak.224 Irrigation or watering is needed for a healthy windbreak. Because the eucalyptus needs large amounts of water for growth, adequate watering is essential or the lateral roots from the windbreak trees will rob and stunt the trees that it is protecting. Some growers have dug trenches three to four feet deep between the windbreak trees and the orchard trees to stop lateral root extension.225
Eucalyptus timber has been put to similar uses similar as other hardwood. It has had some success, but it has failed as well. Its failure is really a misconception in the minds of growers and investors. They were expecting too much from the young eucalyptus trees. They were anticipating products like those produced in Australia. The problem was those products came from eucalyptus trees in virgin forests which were several hundred years of age. The quality of the wood from these older trees differs greatly from the young eucalyptus trees found in California. This misunderstanding meant economic ruin for some in California. It also gave the eucalyptus a bad reputation which still exists today.
Settlers in Australia used the eucalyptus trees just as pioneers in California used the oak and redwoods. They needed shelter, vehicles for transportation, household amenities, and fuel for survival. Eucalyptus timber was used in the construction of ships, buildings, bridges, wharves, and railroad cars. It was used in the manufacturing of barrels, paving blocks, agriculture implements, and furniture. It was also cut for poles, posts, and pilings. The eucalyptus was instrumental in the successful settlement of the vast Australian continent.226
Shipbuilding was an important industry in eastern Australia and in Tasmania. The towering blue gum supplied timbers for the construction of a multitude of ships. There was a certain pride in this effort as seen in this excerpt:
These early Tasmanians were unusual men, their achievements and characters were amazing and the ships they built so sturdy that Time could not destroy them. When they wanted ships they built them, not always in properly appointed shipyards, but often in creeks or on beaches or river banks, wherever suitable tall trees grew. These big- hearted men felled the trees, pit-sawed them by hand power into planks, beams, keels, and frames, to shape their vessels which were to brave the ocean storms and the dangers of uncharted coasts. And they carried the name and fame of Tasmanian ships and seaman over the seven seas.227
These blue gum ships sailed into San Francisco Bay loaded with men and supplies for the California gold fields. These ships served as vivid examples of what the eucalyptus could do. They showed the utility and toughness of the wood. Australian eucalyptus timber was imported for a number of years until the eucalyptus in California reached some maturity.228
POSTS, PILINGS, POLES, and RAILROAD TIES
One of the early uses of California eucalyptus was for fence posts. The blue gum grows quickly, is straight in form, and was grown on ranches. Its wood is hard and strong but less durable in the ground than other species, such as sugar and red gums, but nonetheless it was a popular fence post tree.
Experiments were done early this century testing the durability of the various eucalyptus species in soil. It was found that treatment with creosote extended the groundlife of any post dramatically.229 When treated with creosote, eucalyptus posts would last between eight to ten years. They still would split and check though once dry. Also it was hard to drive a nail into the dried wood.230 These problems stifled their usage.
Eucalyptus timber was used as pilings for wharves along the coast and also to support roadways. Pine was the acceptable timber, but eucalyptus was used in a number of wharves. The enemies of pilings along the Pacific Coast are the teredo and limnoria worms. They can do immeasurable damage literally destroying wharves within a short period of time. These worms are transported from wharf to wharf by ships.231
The teredo lives under water while the limnoria lives at the waterline and does the most damage.232 The teredo is about four inches in length and eats up and down a piling. The limnoria on the other hand is the size of a pin and eats across the grain sawing the piling in half. These worms can destroy a wharf in seven years.233
Eucalyptus pilings proved to last longer in salt water than pine or even redwood. Most eucalyptus wharves had a last eight to fourteen years depending upon the species and the treatment of the wood.234 Wharves at Crescent City, Oakland, Port Harford, Gaviota, Serena, Summerland, Avalon, and San Diego used eucalyptus pilings.235 Oceanside and Santa Barbara piers used eucalyptus as well as reported by A. J. McClatchie in 1902. He also wrote that Abbott Kinney of Santa Barbara in a ten-year period had sold $10,000 worth of eucalyptus timber for pilings.236
Eucalyptus pilings were usually 30 to 35 feet in length and had a diameter of 12 to 24 inches. In 1908 they brought $5 to $15 on the stump.237 It always has been difficult for eucalyptus to be fully accepted as a piling wood. Some wharf managers went so far as to hide the eucalyptus pilings from the public by placing a pine piling in front of them. Once the eucalyptus piling outlasted the pine one, the public was told of this.238
The eucalyptus species jarrah resists the worms the best. In 1894, it was said that had jarrah been used in the San Francisco wharf that it would have saved the city $25 million over a period of forty years!239
Manna and blue gum timber was used in construction along the Santa Ana River in Orange County early this century. A causeway between Ventura and Santa Barbara used blue gum pilings as well. Though sugar, gray, and red gums are more resistant to decay, blue gum was the choice because of its availability to these projects.240
Normally Oregon pine and cedar were used for telegraph and telephone poles. Eucalyptus was tried as noted in this 1908 excerpt, "Eucalyptus poles have been tried to a limited extent, and may be expected under treatment to outlast the pole timbers in present use."241 In Tasmania, just prior to 1876, a construction supervisor reported, "We used for poles young trees of the Blue Gum, White Gum, Red Gum, and Stringy-bark, taking only the bark off. We charred the butts as far as they went into the ground."242 Once again, the timber used in Tasmania was from virgin forest prime for durability and strength. The younger and weaker California eucalyptus never reached this grandeur and subsequent respect; and consequently, it saw little use as telegraph and telephone poles.
In the late 19th century, Southern Pacific Railroad experimented with
blue gum railroad ties in Nevada. A few hundred green and untreated ties
were laid in sandy soil in central Nevada. Their strength and wear were
within tolerance, but because they didn't receive proper seasoning and
treatment, they cracked or checked badly so much so that the ties could
not hold spikes. After four years, some of the ties had deteriorated from
decay, but others lasted for eleven years. It was speculated that had these
ties received the proper seasoning and treatment, they could have lasted
much longer. Also other species, such as sugar, gray or red gums, would
have lasted longer than blue gum. The blue gum ties however were considered
equal to ties from second grade southern pine.243
With the eucalyptus boom of the first decade of the 20th century, came a resurgence of interest in using eucalyptus timber as railroad ties and in other railroad related construction. The Santa Fe Railroad bought the 10,000 acre Rancho San Dieguito in northern San Diego County which was about five miles from the ocean. Company representatives chose to use eucalyptus timber in their enterprise because of the tree's rapid growth, quality of wood, and its adaptability to railroad purposes. The hills and hillsides were planted in trees while the valleys were in planted with alfalfa and flowers. It was aesthetics with economics.244
The railroad company planned to used the eucalyptus wood for ties, posts, and finish work inside the railroad cars.245 It needed three million ties a year which could be easily satisfied by a production prediction of seven million ties a year once the eucalyptus forest had reached maturity of eighteen years. They expected to cut alternate rows of timber for posts after five years. Proper amounts of groundwater seemed to be available and rain would supply water too. The trees were expected to do well in this environment.246 Three thousand eucalyptus seedlings were shipped from Australia and planted at Rancho San Dieguito.247
Shortly, Santa Fe Railroad had the same problems with the eucalyptus timber as the Southern Pacific Railroad had decades earlier. It wouldn't hold spikes because it split and checked. The eucalyptus ties simply didn't weather well. Soon the project was dropped, and the railroad sought other types of wood.
Over the years the untouched eucalyptus forests at Rancho San Dieguito grew lush and verdant. After World War II, Santa Fe Railroad turned the land into a residential development giving it the name of Rancho Santa Fe. A Spanish theme was applied to the development, and the land was bought up by celebrities, such as Douglas Fairbanks, Jr., Robert Young, Victor Mature, and Bing Crosby, who built elegant homes on their properties. There is a local ordinance which reads, "Removal of eucalyptus is prohibited."248
USES AS A HARDWOOD
Many species of eucalyptus produce hardwood of quality and beauty which is comparable to most U.S. hardwood. In 1908 this was written: "The timber eucalypts furnish hardwood possessing qualities similar to those of Eastern hickory or ash. The wood differs in strength and durability, but in general the timber is very strong, heavy and hard, with a close-grain and homogeneous structure."249 At the time of this writing, the United States was in the midst of a hardwood scare which provoked great interest in the fast-growing eucalyptus as a solution to the deteriorating hardwood supply.
California has no natural hardwood; consequently, it had to be imported at considerable cost. Planing mills in California, just before and after the turn of the century, used both California and Australian eucalyptus in their wood products. These mills and woodworking shops could be found in San Francisco, Los Angeles, and San Jose. Because most considered eucalyptus to be just firewood, there was a reluctance to use it for finished products. But the mills and shops persevered with a certain craftiness as seen in this statement made by a planing mill owner: "Seasoned blue gum timber has been substituted in San Francisco for orders for maple, hickory, and 'ironwood' without the knowledge but to the entire satisfaction of the purchaser."250
In 1910, T. J. Gillespie, manager of the Hardwood Planing Company of San Jose commented that his shop was " . . . operating almost exclusively in eucalyptus wood because it is the best hardwood in California today for high grade work. This wood is used in lieu of a second hickory, ash and oak, and is considered equal to any of them."251
In a letter from the Hughes Manufacturing & Lumber Company of Los Angeles, dated December 20, 1909, the company proudly remarked that it had been using eucalyptus wood for three years in interior finish work for cabinets and paneling. It was responsible for the interior work in the Grosse building in Los Angeles which received high acclaim for its beautiful mahogany-like panels. The Hughes letter continued in its praise of eucalyptus wood:
The wood is fully as strong as oak or hickory. When properly cured, it is as free from warping or checking as any hardwood we have. In fact, in view of the scarcity of oak, the many uses to which eucalyptus is adaptable, it will doubtless become the hardwood of the future.252
Hughes Manufacturing had a steady supply of orders and wished that there was more eucalyptus wood available. Besides paneling, Hughes sold flooring board which ran $65 to $75 a thousand feet for 3/8 inch cut and $110 for 7/8 inch.253 The species red gum and gray gum show a beautiful mahogany finish. The blue gum was used in interior trim, furniture, and flooring and would take any color of stain.254 Hughes Manufacturing was completely satisfied with the results received from eucalyptus wood.
One veneering plant in California reported it used eucalyptus. Several shops used eucalyptus in furniture but not in any sizeable production.255 One source noted that John Breuner Furniture Company of Sacramento and San Francisco had manufactured eucalyptus furniture. The company commented, "It (eucalyptus) works up very nicely, does not check, is very close-grain and takes a very beautiful finish, dainty, rich and attractive, equal to natural finished mahogany."256
Breuner's has no record of this activity per correspondence by this writer. Also the libraries of the American Society of Furniture Designers and the American Furniture Manufacturers Association have no information on furniture made from eucalyptus. Yet the evidence points to the fact that some eucalyptus furniture was made.
G.B. Lull, State Forester, wrote in 1908, "Seasoned blue and red gum wood has been used to a limited extent for cabinet work and for the manufacture of furniture. Handsome chairs and tables have been made, which are very strong and do not warp, check or loosen at the joints. The wood takes a splendid finish and has been stained to imitate mahogany very closely."257
In the 1920's eucalyptus was used in interior doors. The book entitled Homes & Interiors of the 1920's contains pictures of doors made from eucalyptus. C.H. Rogers of Watsonville grew eucalyptus and had it sawed at a local mill. He then used it in the interior of his house. T.A. Rogers of Oxnard had eucalyptus flooring put in his house which was to believed to be the first.258
Blue gum was used in the manufacture of insulator pins for power poles. The power companies found the pins satisfactory for their purposes and the cost was very reasonable. At one point a manufacturing company in Sonoma produced 125,000 pins a year using twenty-five year old trees. The cut eucalyptus timber was seasoned for six weeks, and the pins didn't crack, warp or check. They proved to be just as strong and durable as high grade black locust.259 Insulator pins were sent to markets in Canada and the eastern United States.260
IT SHOULD BE WELL-SEASONED
Eucalyptus wood needs to be seasoned, and if properly seasoned, it contains similar qualities of other hardwoods. If not seasoned it will crack, check, and warp. Eucalyptus is a tree that absorbs tremendous amounts of water for growth; consequently, its composition is dense and virtually grainless. When it dries it shrivels because of the large water loss.
California eucalyptus trees were generally young sapwood having none of the utilitarian characteristics of the mature trees found in the virgin forests of Australia. To fully use the lumber from the young California trees seasoning was needed. Tests and experiments were done to determine correct seasoning methods. The public was made aware of these seasoning methods, but still there was skepticism and criticism. Many thought this attitude was baseless. Eucalyptus was stigmatized by its image of being a fast growing plant, much like a weed, and was best used for firewood and not much else.
Eucalyptus proved to be more costly to cut and mill than the other available hardwood. Eucalyptus timber would chip at the ends when being processed at a mill causing the workers to allow a foot on each end. To alleviate this problem and the many others, proper seasoning was desperately needed.261
The seasoning process begins first by cutting the eucalyptus during the winter months, followed immediately by sawing the timber at the mill while it is still green. The sawed lumber is then stacked high allowing the weight of the pile to suppress the twisting and buckling tendency of the lumber. The lumber found inside the stack would be sheltered from the elements allowing the ends to cure gradually.262
"S" irons would be tacked into the ends holding the wood together. Also the ends would be painted slowing the splitting process as well. Furthermore, weights would be affixed on the ends to stop the lumber from warping. Air needs to circulate freely through the lumber pile to expedite the curing process. This is done by stacking the pile loosely. Air-seasoning is better than the quicker kiln-seasoning process. Seasoned lumber would be used in a year's time, but two year wait is better.263
A letter from Hughes Manufacturing, dated April 26, 1910, explained its seasoning method used for eucalyptus lumber. The end-product would be finely finished wooden cabinets. The process was the same for oak. Three to four-inch thick planks where placed in gradually-heated water for four to five days, and then slowly cooled and air-dried for several months.
The results must have been acceptable as seen in this excerpt from the Hughes letter: "We have used this wood for the manufacture of bank and office fixtures, furniture, interior home finishing, decoration work, flooring, and for various other uses where a high polish is needed . . . " The letter continues by noting that the wood when seasoned as described above does not crack or warp.264 It is evident from the body of literature on eucalyptus lumber that some sort of seasoning needed to take place before it would be suitable for working.
FOR PULP, PAPER,
Internationally, eucalyptus pulp has been used as a source for paper and fibreboard for years. In Australia, the first eucalyptus paper was made in 1914.265 Today, 85% of eucalyptus wood is used either for pulp or fuel. When the paper industry switched from long to short fibre, eucalyptus pulp became very popular.266 Usually eucalyptus trees that are from five to seven years old are best for pulp which is a shorter growth period than for many other trees.267
The most popular eucalyptus species used for papermaking are globulus, grandis, and camaldulensis. These species have mid to low fibre density which is best for pulp production. There is a constant effort though to create new and better species for the paper industry.268 Nitens and dalrympleana species are proving to be important sources for pulp because they have little bark and are dense.269
Recently, several companies in California have indicated an interest in using eucalyptus pulp for paper and wafer board.270 Worldwide, Brazil and Chile are major producers of eucalyptus pulp. Brazilian plantations can be found in the interior rain forests with acreage expanding daily.271 Chile has been involved in the eucalyptus industry for decades as well as China and Japan.272
AS A BOILER CLEANER
Boiler explosions were common on steamboats plying the Sacramento and San Joaquin Rivers. Scale produced from the muddy water used in boilers would collect on the inside separating the iron of the boiler from the water. When heating took place, the iron would be heated separately from the water. This would generally overheat the iron, weakening it, and hence an explosion.273
A boiler cleaning agent was developed by George Downie of San Lorenzo about 1888. He bought eucalyptus leaves from General Stratton and boiled them in water producing a dark brown liquid. This liquid was the cleaning agent which was poured into boilers eliminating the scale.274 This was done once a month.275 Not only was the boiler cleaner used in ship boilers, it was also used in boilers found in factories in the Bay Area and in the eastern United States.276
A SOURCE OF HONEY
The eucalyptus flowers provide nectar for bees especially when other flowers aren't available. Some species bloom continuously and hence a constant supply of nectar is available. Besides being a food, some claimed that eucalyptus honey could settle nerves and relieve irritation in the mucous membranes.277 Eucalyptus honey has a strong pepperminty taste and odor which makes it less desirable than other honeys.278
Honey provides a farmer with additional income. The best species as recommended by the Santa Monica Forestry Station were sugar gum, red gum, and red iron bark.279 Types of soil and climatic changes varies the availability of the nectar.280
A SOURCE OF FOOD
Outside of honey, Californians have never used eucalyptus for food,
but the Australians have. The Aborigines use eucalyptus roots as a source
of water. They also cook and eat the roots. The flakes from manna gum are
eaten as dessert by children. Dried eucalyptus leaves are fed to horses,
cattle, and sheep.281
Koalas get moisture and food from eucalyptus leaves. It knows which species it likes, and by smelling, it can tell which ones might be harmful. Contrary to myth, koalas aren't drugged by eucalyptus leaves, but rather they have a very slow metabolism which keeps them relaxed. Koalas have a pleasant odor which comes from the eucalyptus food it eats.282
American zoos have fresh eucalyptus leaves flown in to feed their koalas. The Philadelphia Zoo has 40 lbs. shipped from California three or four times a week. The Milwaukee Zoo spends $12,000 yearly on eucalyptus leaves.283 The Los Angeles Zoo found that Koalas eat leaves from seventeen different eucalyptus species but will prefer some over the others.284
By its very essence, eucalyptus has the scent of freshness and purification. It smells healthy, and consequently, its oils have been used in both folk and modern medicine. This writer's own father told of the practice of putting a eucalyptus leaf between the lips of sick people having respiratory problems. The hanging of eucalyptus leaves in houses was common as well as boiling eucalyptus leaves on stoves allowing the pepperminty odor to permeate the air.
The essential oil used for medicinal purposes is produced by boiling eucalyptus leaves in water, condensing the vapor, and collecting it.285 The species amygdalina produces 265.5 ounces of oil from 1,000 lbs. of leaves while globulus produces 134.8 ounces from the same amount of leaves.286 Globulus oil contains about 60% eucalyptol (cineol); whereas, amygdalina oil contains no eucalyptol but produces phellandrene. Both eucalyptol and phellandrene are used in medicines.287
Pharmacopoeias of Britain and United States require 70% cineol in eucalyptus oil. Some species do have that consistency and more.288 But the 70% requirement has been difficult to acquire in California because of the cost of production; consequently, eucalyptus oil is imported from Australia where species can produce the proper amount of cineol more cheaply.289
The Pharmacology of Materia Medica lists the medical uses of eucalyptus extractions. It can be used as a stimulant, aphrodisiac, antispasmodic, and antiseptic. It is used in the treatment of septic fevers, diphtheria, asthma, foetid breath, ulcers (syphilitic and otherwise), infections of the bladder, urethra, vagina, and spongy and bleeding gums. It is used as a disinfectant in gangrenous or foetid suppuration, foul ulcers, and offensive skin discharges.290 It is used too for coughs, lung diseases, and sorethroats. Eucalyptus tea is good for digestion.291 Eucalyptus oil in hot baths serves as a nerve sedative. A popular cure for singers and speakers with sore throats has been "Mission Eucalyptus" used along with Listerine which too contains eucalyptus oil.292
Eucalyptus oil manufactured for medical purposes can be found in several different forms. It comes as a capsule, fluid extract, powered extract, solid extract, elixir compound, inhalant, lozenges, tinctures, and pills.293 All of these preparations have a strong pepperminty odor. On the tongue and in the stomach, eucalyptus oil produces warmth. If taken internally, large doses can produce headaches, and fatigue. It can cause death in animals from paralysis.294
In 1895, Abbott Kinney reported examples of medical success. A doctor in Kansas used eucalyptus extract to heal an amputation which healed well with little pain.295 A Dr. Wooster of San Francisco used eucalyptus medicine in 136 cases of various infirmities in which 106 were cured. A Dr. Keeler in Australia treated 432 cases with eucalyptus extract, and 310 were cured. These are just two of the many examples found in Kinney's report.296
Eucalyptus tincture has been used in the treatment of wounds and sores. Tincture is produced by putting macerated leaves in alcohol for three months. Ten lbs. of leaves gives 25 quarts of tincture.297 Aborigines of Australia used eucalyptus leaves as poultices on wounds. There was one case where an Aborigine had a wound where there was a protrusion of his intestines. They were pushed back into place and dressed in a poultice of eucalyptus leaves. He healed.298 It was reported in 1871, that hospitals were using eucalyptus as bandages.299 It was becoming more evident that the eucalyptus had healing powers and should be used medicinally.
At the 1888 World's Fair in Melbourne, Australia, there were 26 cases of diphtheria. Patients breathed steam produced by boiled eucalyptus oil in water. They were able to cough up the balls of tough white mucus. All but two patients fully recovered.300 It was used too to cure dysentery which settlers and miners contracted.
Eucalyptus was sprayed once or twice a day in sick rooms to disinfect unhealthy air.301 Eucalyptus seedpods, called portieres, were draped inside houses to emit a healthy scent. It was felt asthmatic patients found relief breathing the eucalyptus-treated air. Eucalyptus oil was used by the rich and poor alike. The Stanford family of Palo Alto used eucalyptus oil as medicine as reported by Leland G. Stanford in a 1970 article.302
The English settling in Australia used eucalyptus as a medicine. Its smell reminded them of their English peppermint. It was used for colic, dysentery, and diarrhoea. In the gum secreted by the eucalyptus is found the ingredient kino. Taken internally kino is good for intestinal disorders. A factory was established in Australia to produce peppermint gum oil a cure for many ailments.303
Eucalyptus species that have a small amount of foliage will have a high level of kino. Rostrata, resinifera, marginata, diversicolor, and siderphloia are of this type. Rostrata posts and poles lasts the longest in the ground because of its kino content.304 Kino is similar to the resin found in pine trees.305
At the turn of the century, a Los Angeles physician was able to produce and sell nine tons of oil which was used in a salve, soap, and cough drops.306 H.B. Silkwood of Garden Grove produced one ton of oil from one hundred tons of material to use in medical products.307 Eucalyptus oil came primarily from blue gum in California because it could be manufactured and sold profitably. J.C. Mitchell of Garden Grove could extract three to four gallons of oil from two tons of leaves and twigs. The cost of processing was $3 a gallon. In 1908, it was reported that California distilleries were having trouble finding a market for eucalyptus oil308 because eucalyptus oil from Australia was sold for a cheaper price.
Today, the world market uses 2,000 to 3,000 tons of eucalyptus oil a year. It is mostly a disinfectant,309 but it is also used in perfumes and flavoring. The major producers of this oil are China, Portugal, Spain, Chile, South Africa, and Swaziland.310 The oil's odor is very noticeable but non-toxic. A bottle of eucalyptus oil was accidentally broken at Dulles International Airport in 1992. Twenty people were hospitalized, a terminal was closed, and thirteen flights cancelled. This was resultant of its pungent smell not because it hurt people.311
Recently in California, because of the malathion spraying to eradicate the med fly, eucalyptus leaves have been boiled and inhaled to clear one's respiratory system affected by the spray.312 Products being manufactured today using eucalyptus oils are ointments, such as, Vaporub. Health stores sell rubbing agents containing eucalyptus which are used for sore muscles and joints. Eucalyptus oil is used in saunas and spas for its healing vapors and sedative powers as a muscle relaxant.313
One of the most enthralling chapters in the history of eucalyptus is its relationship to the eradication of malaria. Throughout the nineteenth century, it was believed that the eucalyptus fought malaria simply by disinfecting the ground and air. By the end of the century, the cause of malaria was found, and the eucalyptus' true relationship to the disease became known.
The female anopheles mosquito carries the malaria parasite and implants it in a human's blood system. The mosquito's home and breeding ground is generally in a area of standing water such as swampland. Because the eucalyptus absorbs large amounts of water, it can drain swampland thereby destroying the habitat of the mosquito, and consequently stopping the spread of malaria. But the story of malaria and the eucalyptus before this was known is fascinating.
As in any mystery there are theories. Early on there were many theories of how the eucalyptus miraculously stopped malaria. Also there were glowing accounts of real life experiences of the successes made in the fight against malaria by the eucalyptus.
Very few people know that California had malarial problems. Malaria could be found in the Sacramento Valley and Kern County last century. In the Third Biennial Report (1874-75) of the California State Board of Health, the secretary of the board, Dr. Thomas M. Logan, was the author of a section entitled "Malarial Fevers and Consumption in California." Much of the report was about the eucalyptus and its ability to suppress the spread of malaria. He reprinted a contemporary article taken from the Kern County Courier reporting on one farmer's experience with malaria and eucalyptus:
In regard to the anti-malaria influence of the eucalyptus, we have this conclusive evidence. We have given it what we regard as a reasonably fair test on our own farm. This is cultivated by two families, or companies, of Chinese. One company lives near the north and the other the south end of the premises, about three-fourths of a mile apart.
The localities both parties inhabit are favorable to the development of malaria. The soil is rich, moist, and teeming with vegetable life, and the free sweep of the prevailing wind is obstructed by the intervention of dense thickets. As might be expected, they
have, every year, during the heated term, suffered with malarial fever. Last winter we determined to test the much vaunted virtues of the eucalyptus.
In February we gave to the party at the north end two ounces of the seed with the directions that it should be planted near the house. It germinated finely, and produced several thousands of young plants, but the frost killed most of them. About twelve
hundred, however, survived. These, when the heated term commenced, had attained an average height of two feet, and emitted a strong aromatic or camphorous odor, perceptible at a distance of a hundred yards.
In due time the party at the south end were visited by their usual mildly distressing fever, but up to the present time we have looked in vain for the first symptoms to develop in the other. They are all, to their own astonishment, in the most robust health. These trees now average more than three feet in height, and the atmosphere of the house is strongly impregnated with their odor . . . and propose, the coming season, to plant it on all the waste places and corners on our farm we can spare from the other purposes. If everybody would do likewise, the great valley of Kern County
might soon take rank among the sanitariums of the State . . . " 314
Concluding, Dr. Logan wrote, "These evidences go far to establish the
fact that the eucalyptus globulus has a good effect in preventing the spread
of malarial diseases . . . "315
In the California State Board Health's Tenth Biennial Report (1886-88) appeared an article with the title "Irrigation and Forestry Considered in Connection with Malarial Diseases." Use of eucalyptus and other plants were being used to stem the spread of malaria as seen in this excerpt:
It is a well established fact that in malarial districts the planting of shrubs and trees has had the effect to greatly modify, if not entirely remove, the malarious influence . . . But wonderful far efficacious than all, owing to the rapidity of its growth, its wonderful powers as an absorbent, and the balsamic exhalation of its essential oil, it is Australian blue gum tree (Eucalyptus globulus).316
Dr. W.P. Gibbons of the Medical Society of the State of California wrote, "It has not been proved, though asserted until belief is established, that the aroma of the eucalyptus is effective in preventing the incubation of intermittents."317 The scientific and medical fields knew that the eucalyptus arrested malaria but didn't really know why. The assumption by some was it was disinfected the air.
There were numerous reports worldwide of the success the eucalyptus was having in treating malaria. In 1874, the periodical California Horticulturalist contained such reports. For example in Cape Colony in southern Africa came this testimony: "In the spring of 1867, I planted upon this farm 13,000 plants of the Eucalyptus globulus. In July of that year, the season in which the fevers appear, the farmers were completely free from them . . . "318
Another example is this report from Constantine (Turkey) where eucalyptus had been planted: "The atmosphere is constantly charged with aromatic vapors, the farmers are no longer troubled with disease, and their children are bright with health and vigor."319
M. Gimbert in 1874 made these comments before the French Academy of Sciences concerning the eucalyptus:
A tree springing up with incredible rapidity, capable of absorbing from the soil ten times its weight of water in twenty-four hours, and giving to the atmosphere antiseptic camphorated emanations, should play a very important part in improving the health of the malarious districts . . . it has the property of absorbing directly from marshes, thus preventing fermentations which are produced, and paralyzing the animal miasma proceeding from them which might arise from them."320
During this period of time, throughout the world, the eucalyptus was labeled "fever tree" because it generally stopped the spread of deadly fevers. In Valencia, Spain, eucalyptus trees had to be protected by guards to prevent leaves from being stripped off by its citizens.321 And what did the Australians think about their treasured native tree and malaria?
In 1876, J. Bosisto read a paper before the Royal Society of Victoria (Australia) entitled, "Is the Eucalyptus a Fever-Destroying Tree?" He opened with this statement:
Its (eucalyptus) power to absorb considerable moisture, and to permeate the air with its peculiar odour, led to the belief that this tree . . . exerts a beneficial influence upon malarious districts . . . is the eucalyptus a fever-destroying tree? Or, in other words does it tend to lessen malaria or to destroy miasmatic poison?322
Bosisto then tells of his investigations in Australia, commenting: "Australia on the whole may be said to be pretty free from virulent endemic or miasmatic fevers, and the latter may be said to exist only as the eucalyptus recedes."323
After analyzing eucalyptus oils and resins, Bosisto was not able to find anything in them that had the power to oxygenate and purify the air more so than other plants.324 He noted that eucalyptus oils permeating the air, did refresh one's breathing.325 Bosisto concludes his paper with some support of the eucalyptus' value in fighting malaria, but the question is still virtually unanswered. He wrote, "In conclusion, may we not say with some authority that the evidence set forth in this paper on our own vegetation is in favour of the eucalyptus being a fever-destroying tree?"326
The most famous case concerning eucalyptus treatment of malaria comes from the Tre Fontaine Monastery near Rome, Italy. Each year during the "fever season," the monks would come down with malaria. Swamps were near, and the monks worked the fields returning to the monastery at night. It was thought that the night air carried malaria. Eucalyptus trees were planted in the swamps reclaiming the land with their ability to drain the water through their root systems. With the water gone the mosquitoes had no habitat in which to breed and carry on activity. Malaria fever greatly lessened, but a Dr. Montechiare, who was a physician for years in that area, was not convinced that eucalyptus affected the disposition of malaria.327
Scientists and physicians knew that the eucalyptus did something to interfere with the process of malaria, but what it did and how it did it wasn't clear. Many simply disclaimed it until the cause of malaria was found.
In California, malaria reached its peak in the 1880's. Blue gums were planted with fervor because it was generally felt they purified the air and had some effect on malaria. This comes from the Pacific Rural Press:
A paper read before the California Academy of Natural Sciences in 1879 reported that the Southern Pacific Railroad had planted 1,000 eucalyptus trees between the train stations and the marshes to ward off malaria in the interior valley. The number of malaria cases had dropped from twenty-five to eight.329
It was thought that malaria came from moist, rich soil escaping into the night air during the summer months. Night air is usually damp and chilly, and thought to carry a multitude of maladies of which one was malaria. The word "malaria" in Latin means "bad air." By virtue of its aroma, it would be only natural to suppose that the eucalyptus somehow purified the "mal aria" or bad air.
It was also thought that the oils dropping from the eucalyptus leaves and the gums secreted from the bark, disinfected the ground around the tree. These secretions had a purifying effect just like its aroma did to the surrounding air.
In his 1895 work, Eucalyptus, Abbott Kinney gave many examples of the success eucalyptus was having in arresting malarial fever. Some of have been noted above. Kinney thought that malaria entered the body through the ingestion of water, milk, or food. The malarial germ, he felt, was released into the air by turning over soil in warm, marshy land, and some way it got into what humans ate or drank. He cited Bakersfield cases where unboiled water from shallow wells (he felt) caused malaria. He called it the "Bakersfield Fever." After the water was boiled from these wells the malaria disappeared he reported.330 Kinney did experiments with meat, water, and eucalyptus leaves. He wanted to see if eucalyptus stopped the growth of bacteria. In results were inconclusive.331
The connection was beginning to be seen between disease and insects especially mosquitoes. Kinney used an eucalyptus smudge to kill mosquitoes, but it didn't work.332 The Pacific Rural Press reported in 1876, " . . . being very much in his sleep by mosquitoes, took it into his head to place a young plant of eucalyptus in his bedroom over night. From that moment the insects disappeared and he slept in comfort."333 There was a doctor who rubbed eucalyptus leaves on his horse to drive the insects away. Pillows were sprinkled with an eucalyptus powder to keep insects off them.334
The Tulare Register ran this testimony: "Our house was surrounded with blue gum trees. We always slept with our doors and windows open and were never seriously bothered while just a few rods away the stock would be covered and almost perish with the great numbers (mosquitoes) tormenting them."335
Finally the cause of malaria was known. In a 1900 issue of The Forester, published by the American Forestry Association, there was an article entitled, "The Eucalyptus in the Tropics: Its Rapid Growth and Value as a Sanitary Agent, Acting as a Preventative of Malaria." It told of the cause of malaria, and urged the planting of eucalyptus to dry up swampland thereby removing the mosquito's breeding habitat. The article went on to discuss the positive effect eucalyptus had on the air.336 This theme could be seen too in the 1897 yearbook of the U.S. Department of Agriculture:
With regard to the sanitary value of the tree, it has been strongly stated that its value was owing to its rapid growth and the great absorbent power of its roots in drying up wet and marsh lands, but it is no longer doubted that Eucalyptus globulus, along with other species of Eucalyptus, evaporate with water a volatile oil and a volatile acid, which permeate the atmosphere and contribute to its invigorating and healthy nature and character.337
The eucalyptus had found its place as a partner in the prevention of malaria, and it still held its usual stature as an agent in cleansing the air. The latter would last until
modern medicine got more sophisticated and became disinterested in old-fashion ideas of treatment or "sanitation."
FOR LANDSCAPING AND
One area in California where the eucalyptus has had a high profile certainly is in its presence along the roads and highways of the state. With its willowy silhouette cast against the hills and flatlands, it pleases the mind with its picturesque form. It is a reminder that there is something more to our world than asphalt, steel guardrails, and automobiles. It gives us a glimmer of a peaceful past when humankind turned to the natural world for answers instead of to science and its automaton creations.
One has only to drive along the coastal foothills of this state to became immediately aware of the dark forests of eucalyptus hugging the hills and gullies. As the eye sweeps across those images, there is a stirring inside finding expression in aesthetic pleasure and a recognition that those forests belong there. The eucalyptus did indeed change California horizons as expressed by Kinney in 1895:
The introduction of this tree has done more to change radically the appearance of wide ranges of country in California than any other one thing. In the reclamation of many arid plains of the central and southern parts of California the blue gum has worked almost like magic. It modifies the winds, breaks the lines of view all so quickly that one can scarcely realize that a valley of clustered woods and lines of trees was but a year
or two before a brown parched expanse of shadeless summer dust. I do not think that the power of the blue gum in modifying the appearance of a country can be appreciated by any one who has not seen some stretch of country before and after its introduction.338
Tree shade is something that humankind has always appreciated. On hot summer days, tree shade is not only refreshing, but it is part of survival. One of the earliest
uses of the eucalyptus was for ornamentation and shade. Eucalyptus were planted along country and some city roads for beauty and for the practicality of shade.
Of the eucalyptus species blue gums were first used, but their size and aggressive root system made them more of a liability than an asset. Their roots tore up sidewalks and streets. They were too big to prune, and dripping water from them made the graveled roads muddy. Many were removed. It was simply a problem of finding the proper species.339 Today smaller and less aggressive eucalyptus are used.
Route 160 near Rio Vista has the oldest remaining roadside eucalyptus. They were planted over one hundred years ago along the levee road. In the 1890's in southern California, eucalyptus were planted along roadways to halt gusting winds.340 This was done too in the 1930's on the highway west of San Bernardino.341 In 1913 a law was passed to give power to the county boards to oversee the planting of trees along the roadside. The purpose of the legislation was to encourage communities to plant trees for beauty, shade, and windbreaks.342
In the 1930's more legislation was passed. Route 91, from Fresno to Bakersfield, has eucalyptus along it primarily because of that legislation. In the 1950's, along Highway 99, from Marysville to Modesto, the species sideroxylon was planted.343 These are just a few examples of highway planting. If one gets off the beaten path and travels on an old highway, there will be evidence of early eucalyptus roadside planting.
The use of eucalyptus along roadways continues today. The species have changed. In 1961, CalTrans planted camal- densis, citriodora, caldocalyx, polyanthemos, rudis, and sideroxylon. In the 1980's, 11,000 caldocalyx, 10,000 camaldensis, 6,000 sideroxylon, and 3,000 rudis were planted along highways.344
CalTrans' present plan is to plant eucalyptus as (1) part of the urban landscape (2) part of the rural aesthetic especially in the dry areas of the Central Valley and southern California (3) to define the highway's borders (4) windbreaks for safety and to prevent soil erosion (5) sources of chips for mulching to be used planted areas.345
CalTrans did a study in Sacramento recently on drought and the eucalyptus. It found that these three species are drought tolerant: dalrympleana, parvifolia, and annulata. However, for most eucalyptus species there was modest survival rate.346 Trees that are used in roadside landscaping are selected for their adaptation to the local climate and for their overall usefulness to the roadway.