Activities of the U.S. Plant Introduction Garden
|Activities of the U.S. Plant Introduction Garden|
An introduction garden, primarily for the development, appraisal and distribution of tropical plants, has been conducted by the Department of Agriculture in this region since 1898 when the first garden was established on Brickell Avenue in Miami on 6 acres of land. It was not long until this area became crowded with plants and another, somewhat supplemental garden of 25 acres, was begun in 1914 on the north side of Miami in a subdivision known as Buena Vista. By 1921 half of the Buena Vista Garden and all of the Brickell Avenue Garden had been planted and consideration was being given to some further area for expansion. Late in 1921 it came to the attention of Dr. W.A. Taylor, Chief of the Bureau of Plant Industry, that the Chapman Field Military Reservation southwest of Miami was to be abandoned by the War Department, and Dr. David Fairchild was asked to investigate its potentialities for use by the Bureau of Plant Industry. On the basis of the opinion of Dr. Fairchild and others familiar with local conditions and tropical plant requirements, a request was made for transfer of the Military Reservation from the War Department to the Department of Agriculture for use as a Plant Introduction Garden. While direct transfer was not made, a permit for use of the Reservation for such a garden, revokable on three years notice, was issued to the Department of Agriculture on Dec. 15, 1922. At a later date the area covered by the permit was reduced to 95 acres containing all the improvements of the Chapman Field Reservation. For many years, this area plus an additional 65-acre pinewood area used under an extendable 5-year permit for rubber planting, constituted the U.S. Plant Introduction Garden, but in 1947 the 80th Congress transferred title of these 95 acres, the 65 acre pinewood area, and an additional area of approximately 37 acres from the War Department to the Agriculture Department.
The first permanent planting was made at the U.S. Plant Introduction Garden at Chapman Field on April 26, 1923, and in the next three years much of the material that had been grown at the Brickell Avenue and Buena Vista Gardens was transferred here. In September, 1926, a very severe hurricane swept the Miami area and did great damage to the early gardens, and thereafter they were abandoned, most of their introduced plants having been established at the new garden.
At the present time, approximately 125 acres are developed in plantings or ready to receive them, and this portion as well as the unimproved areas are completely enclosed by a 5-foot chain link fence.
Throughout the older portions of the present garden, the system of roads laid out by the War Department during World War I has been maintained with unimproved roads being made throughout the more recently acquired sections.
The majority of buildings now on the garden grounds are of masonry construction and not subject to rapid deterioration or high maintenance costs. These buildings consist of two office buildings, two large garages with workshops, a large and a small potting and packing house, a small greenhouse and two large greenhouses and a large lathhouse, two laboratory buildings, a millhouse, a large fertilizer mixing and storage building (wood), a combination tractor shed and pump house, four storage buildings of varying sizes, four residences plus three small buildings for the accommodation of single employees or visiting scientific workers.
By far the largest part of the garden is of what is known locally as "high pine land," being from three to twelve feet above the water table and composed of very porous and rather soft oolitic limestone with only a thin covering of sandy soil except in certain pockets of varying size, where the soil may extend down to the ground water. On the east side, the high pine land drops off to what once had been mangrove swamp, but in 1917 was filled with dredged marl soil to form a level airfield a foot or two above mean high tide. This combination of high, rocky, and sandy land and the low marl-filled area, gives opportunity for testing introduced plants under the extremes of soil conditions as they occur in this region.
Since the inception of the garden, over 14,000 plant accessions have been received; the average per year thus being nearly 500. These accessions have come in the form of seeds, cuttings, budwood or plants sent from every part of the subtropical or tropical world, and representing almost the entire range of terrestrial plant life. A large proportion of these introductions have come from professional plant explorers sent out by our Headquarters Office, originally in Washington, but some years ago transferred to Beltsville, Maryland. Others have been received in the foreign seed exchange program maintained by our Section of Plant Introduction. Still others have come through correspondence with foreign sources, as voluntary gifts, or in minor numbers through other channels.
Most plant accessions come as seeds usually planted on the day they arrive. The resulting seedlings, as well as other propagating material, are grown to a size suitable for planting in the field. Except in special cases where larger representation is needed, four plants of each introduction are set in permanent places in the field with several held in reserve for replacement of field failures. Where seedlings or plants from other propagating types can be grown in sufficient numbers, they are offered to cooperators or experimenters who have facilities for growing and reporting on the plants they receive. These bulk distributions are made in the Spring of the year in order to give the plants issued time to become established in their new homes and make growth before the following fall and winter.
Bulk distributions of plants, based on circularized lists from Headquarters, have been made yearly from this garden since its establishment, with the exception of 1948, when a reduced Staff and budget interfered. In the last 15 years, not including 1948, nearly 84,000 plants and packets of seed have been issued to a total of 2532 experimenters and cooperators, an average of 169 recipients receiving 33 plants or seed packets each per year.
Where plants of other species are too few for the general distribution, outstanding ones may be put on special lists offered to plant institutions such as State Experiment Stations, botanic gardens, University farms, etc. Residues from the above distribution are given in small numbers to persons, on neither distribution list, who make special requests for them.
In addition to plant distributions, special requests for seeds or other propagating material from our mature plants usually are filled where such material is not readily obtainable from commercial sources.
Aside from the foregoing seed and plant distributions, year-round collection of bulk seed samples from our mature field plants have been made, and the seed sent to our Headquarters Office for the Foreign Seed Exchange. The number of species from which seed is collected has gradually increased through the years as more plant introductions matured, until at present over 400 species are included in the list of those available.
The practice of setting in our fields a few plants of each introduction received has now resulted in establishing a botanical collection of tropical and semi-tropical plants not equaled elsewhere in this hemisphere, and surpassed by few gardens in the East.
Introductions of Indian and Philippine varieties of mangos and extensive collections of avocados from Mexico and Central America have been established here, and distributions of them have contributed directly or indirectly, through supplying parents for present day varieties in the development of the extensive commercial plantings of both these fruits in this country.
Many of the smaller tropical fruits now widely grown here came through this garden as introductions from foreign countries.
Of incalculable value to the horticulture of this country are the host of ornamental palms, trees, shrubs, and vines first introduced through the Introduction Gardens of this region. An outstanding importation in this category was Centipede grass, that has proved to be one of the best lawn grasses of the region, and was discovered in China in 1917 by one of the foremost plant explorers sent out by our Headquarters Office.
At present, an estimated 2000 to 2500 plant introductions are growing in our fields. Contained therein are approximately 65 species of Ficus; 50 Eucalyptus species; 35 species of tropical Bamboo, 150 species of palms; 15 identified species of Strophanthus, and several unidentified species and relatives; 20 Terminalia species; and 15 species of Bauhinia. Varietal collections of avocados, mangos, lychees, jaboticabas, guavas, hibiscus and pineapples also are maintained.
The large aggregation of tropical plants represented here has attracted many botanists, both systematic and economic, who have studied, classified, and gathered specimen material of the species. Among these botanists who have used our collections extensively may be mentioned Dr. L.H. Bailey of Cornell University, Dr. Ira Condit, Riverside, California, Mr. Oliver M. Freeman of the National Arboretum, Dr. H.E. Moore, Cornell University, Dr. F.H. McClure, U.S. Dept. Of Agriculture, and Dr. Erdman West, Univ. Of Florida, Gainesville, FL. During World War II the garden was used for the training of Air force personnel in tropical survival studies using plants that would be found throughout the tropics to yield food, or provide materials of aid in survival in the jungles or on the sea. Toward the end of the war, we frequently received word that lessons learned from these studies had been instrumental in saving the lives of Air corpsmen falling in enemy territory.
The garden is extensive and frequently used by local Garden Clubs for study of exotic plants, methods of seed sowing and general propagation. In addition to such groups the Garden is visited daily by persons touring the grounds or having special problems to be answered. School and University classes also use the garden occasionally for conducted tours of botanical interest.
In the last several years, active interest in plant antibiotics, heart drugs, cortisone-yielding plants, and in miscellaneous drugs has increased, and the plant collection of the garden has been drawn upon extensively to supply materials, not otherwise available in the United States, for analysis. In this program, which is being continued here, multiple samples consisting of leaves, stems roots and fruits of 818 species have been sent to Dr. M.E. Wall, of the Eastern Utilization Research Branch, Philadelphia, PA. And similar samples from 605 species have gone to Dr. John E. Little, University of Vermont for antibiotic study. Specially requested samples, often consisting of fifty pounds of material, from approximately 20 species have been sent to the Heart Institute in Washington, D.C. for analysis.
Since 1923, a comprehensive collection of rubber-producing plants has been gathered and maintained for appraisal of national production possibilities in times of stress, studies of physiological and chemical formation of rubber in the plants, methods of harvesting rubber from the various species, etc. Of greatest importance in theses studies has been the Para Rubber tree, Hevea brasiliensis from which nearly all natural rubber comes. It was early found that this strictly tropical species would grow well in the deep-soil of Dade County, and could withstand our hurricanes and light frosts with little more than temporary setbacks. Also, it was found that the tree was not attacked by the serious diseases affecting it in tropical plantations, that it fruited well, in fact, that many of the selected varieties flowered from two to five times a season in contrast to the single flowering that took place in the tropics. This fact has been used to effect intercrossing of varieties that do not have synchronous flowering under plantation conditions. In recent years, this garden has been designated as a Hevea Quarantine Station where desirable clones are being grown, free of disease, and from which budwood is shipped to any part of the wold without fear of transporting a serious disease. To further this program, as well as that of breeding, over 260 of the World's best clones have now been established here, and are being increased in numbers each season.
At various times in recent years, natural rubber chemists have taken advantage of this aggregation of rubber plants from all parts of the tropical world to secure fresh latex and rubber samples for studies that otherwise would require excessive travel and expense to reach the native homes of the plants from which the samples came.
Within the past year a similar quarantine program and accumulation of a clone collection has been established for coffee, with the approval of the coffee-growing countries of this hemisphere. One hundred selected clones already have been set in the field as a nucleus to which others will be added as they become available. Disease and insect-free material from this collection is to be made available to the cooperating countries as needed by them.
Since several species of coffee have fruited well here for many years, the above clone collection is expected to do likewise and thus should offer better opportunities for breeding than are available in most coffee growing countries.
Statewide interest in this garden has been and continues to be high because of the great amount of successfully established plant material from tropical countries that it has introduced and distributed. Many botanical and horticultural institutions in the north and in foreign countries profit from the plants and seeds it has available for issuance. Closer home, most satisfactory cooperative relations of mutual benefit are maintained with such horticultural and botanical organizations as those departments in the University of Florida at Gainesville, FL. and the University of Miami, the Subtropical Experiment Station at Homestead, FL, the Fairchild Tropical Garden at Coconut Grove, FL and the Dade County (Florida) Parks System.