ARBORETUMS, PLACES OF BEAUTY AND SCIENCE

W. H. LARRIMER, ERNST J. SCHREINER.

To the person who has a piece of ground, a few dollars, a love for trees and nature and beauty, a collector's instinct, and an interest in science, we should like to recommend that he start an arboretum. Few things, we think, are more worthy of effort, more productive of abiding satisfaction and accomplishment, and more enjoyable than a collection of trees of one's own.

An acre is ample for 20 or 25 specimen trees and many beautiful shrubs. Five acres is plenty for a really representative collection of trees, which can be underplanted with flowering and fruiting shrubs that will bring bird life and bird songs practically into the home. How much one pays for the trees depends on how much one wants to pay. A few pennies spent for seedlings, to which are added materials started from cuttings and gifts from neighbors, will provide the beginning.

Almost everyone collects something, and enjoyment people get out of their collection whether trees, stamps, or first editions derives in large measure from its completeness. And so the collector of trees and shrubs will do well to set up an objective. It might be to grow one of each of 10, 15, or 20 different species. It might be to grow rare trees, like the franklinia or the offspring of historic trees, such as the Mount Vernon Pecan or the Evangeline Oak. Or it might be to obtain a complete collection of the native trees and shrubs of his county or State. In the Northern States, such a collection will not be excessive in number of specimen plants, but farther south it will entail a great many species. If the objective were to grow all the species of one group of trees, such as pines, maples, or oaks, then the size of the collection would depend upon the group of trees one selects.

Keen enjoyment comes from the search for new specimens to add to a collection. The collector can get some specimen trees from commercial nurseries. But for many rare types and this is one of the joys of collecting he will have to get seeds, possibly from some public arboretum, and to grow the seedlings himself. The collector of native trees might collect seed or wild seedlings on trips through his home State, or on his travels anywhere. Some of them, gathered at a distance, will not grow, perhaps, but that is a part of the art.

An excellent example of a personal arboretum is the Hemlock Arboretum in Philadelphia. The owner, Charles F. Jenkins, aims to grow all the various growth forms of the native eastern hemlock, which are mostly slow-growing or dwarfed forms. His collection in 1948 included 190 specimens, representing 40 varieties.

MUCH THE SAME, except in ownership, is the community arboretum, which deserves the consideration of garden clubs, service clubs, and other organizations interested in the enrichment of community life. Undeveloped park areas or other community property is suitable for an arboretum. A community arboretum should not be confused with a community park that is provided for physical recreation; it cannot become a dual-use area, playground and arboretum.

Sections of new parkways on the outskirts of towns and cities are excellent for arboretums. Such parkways are high-speed arteries, but arboretum areas up to several miles in length can be safely established on long and relatively narrow side strips that need tree planting. Eventually, arboretum areas should be incorporated in the plans for new highways, with provision for additional land where it is required. Visitors to such an arboretum need not interfere with traffic on the main highway; suitable parking areas can be provided in places where the aboretum strip is relatively narrow. A better arrangement for wider strips is to build a gravel side road through the arboretum, parallel to the main line of travel and wide enough to permit parking without interference to traffic.

Many people in towns undoubtedly would enjoy periodic visits to a park or parkway arboretum. School children could be brought out in busses for nature study. If the arboretum is properly identified by signs, many travelers would take time to leave the highway and drive slowly through the arboretum strip.

No arboretum should be started until a plan has been well thought out and formalized on paper. Such a plan should define the purposes to be served, which, in general, determine the space required, what and how to plant, and the costs of establishment and maintenance. The plan should indicate how the project is to be financed. Advice, when it is needed, can be had readily from nurserymen, gardeners, landscape architects, and various other specialists, professional and amateur.

The person, group, or community that establishes an arboretum follows a long and interesting tradition. The dictionary definition of an arboretum as "a botanical garden of trees" indicates that their history is part and parcel of the history of botanical gardens. Such collections of trees, arranged as specimens or in the natural groups and authentically named and maintained for educational, esthetic, reference, and research purposes, have found a place in the botanical gardens of all countries.

WE HAVE RECORDS of some ancient botanical gardens, and it is a safe assumption that trees, and thus arboretums, were an important part of at least some of these gardens.

History records that, 2,800 years before the birth of Christ, the Emperor Shen Ming had a garden in which he grew medicinal plants; and that Thotmes III, the ruler of Egypt, had a pleasure garden planned by the head gardener of the Temple of Karnak about 1500 B. C. Aristotle, the great teacher of antiquity, developed a botanic garden at Athens about 340 B. C. in which he taught his students. It would appear that these ancient gardens were established for three primary reasons utility, pleasure, and instruction.

A wide historical gap exists between the ancient gardens and the botanical gardens of the Middle Ages. As learning returned to Europe with the close of the Dark Ages, gardens were established for the utilitarian purpose of growing and testing medicinal herbs. One such was a medicinal garden at Salerno, Italy, in 1309, which has long since disappeared. Some of the medicinal gardens eventually became botanical gardens and arboretums. In Italy, botanical gardens were started in Pisa in 1543 and in Padua and Florence in 1545. Botanical gardens were established in Germany at the University of Leipzig in 1542 and at the University of Heidelberg in 1593. A tree planted a few years after the establishment of the botanical garden at Leiden, Holland, in 1587 was still standing a few years ago. One of the oldest botanical gardens in France has been in existence at Montpellier since 1593.

The world famous Royal Botanical Gardens at Kew, London, has a particularly large collection of arboretum material. It originally comprised two royal estates, which were first combined in 1802 and became a national garden in 1841. It has been said that probably the largest number of tree and shrub species which has yet been gathered is to be found at Kew.

Tokyo had a well-established garden in 1684. A botanical garden apparently existed on the outskirts of Manila in the Philippines before 1787.

Although arboretums were usually a part of botanical gardens, some early collectors were primarily interested in trees for purposes of ornament and forestry. Rene du Bellay, Bishop of Mans, made a collection of trees at Touvoye, France, about the middle of the sixteenth century; the contemporary botanists called the collection the richest and the most beautiful in France, Germany, and Italy, but it has long since disappeared.

About two centuries later, Duhamel du Monceau planted approximately 1,000 species of trees and woody plants from Europe and North America in the first arboretum established for scientific purposes. His arboretum and publications led to the introduction of many exotic trees into French parks and plantations. Some of his specimens are still living.