OUTDOOR PLANTS FOR DWARFING, BONSAI-STYLE
With proper care, any woody plant—any tree, shrub, or vine with persisting trunk or stems—can be grown indefinitely in a pot. With some skill in pruning branches and roots, it can be permanently dwarfed. And with imagination and artistry, it can be trained to re-create in miniature one of the majestic pictures of nature. However, some plants are more amenable to rigorous dwarfing than others; some adapt more willingly to growing in containers; and some are by nature more suitable in habit and appearance.
The easiest plants to dwarf are those that are naturally small, or slow growing, and those with small leaves or needles, flowers or fruit. Proportion is the most important factor. Every element—leaf, twig, branch, trunk, root, container—must be in harmony and balance with all others.
It’s not impossible to use larger-leaved plants. It’s just a little more difficult. Long needles can be cut shorter, for example, but they must be kept the proper length. Large leaves can be thinned to relieve any feeling of heaviness, and each leaf can be used to represent a branch. With some types of deciduous trees—say, maples—the leaves that come out first in the spring can be pinched off. The leaves that come out to replace them will be smaller.
Almost equally important is the “character” of a dwarfed plant—its irregular or fluid lines, illusion of age, unusual aspect of bark or twig that make it dramatic and vibrant. Any form of art can be dull if it has nothing except perfect proportion to offer. With good proportion, plus intriguing line and design, it becomes interesting.
In the original bonsai the artist transplanted a tree he found growing in the wild and carefully conserved the misshapen lines made by buffeting weather, or he very carefully copied, or re-created, a tree he had seen holding a precarious footing high on a rocky ridge and perhaps dipping down into a windy gorge. These shapes and forms are now the basis for specific classes of bonsai which we can borrow or adapt. So the “character” of a plant may suggest that it be trained as if it were growing out at a right angle from a rocky slope with its roots covering a stone; as a grove, to weep or cascade; or as a gigantic, single-trunked forest monarch with pitted, weather-worn bark.
Or perhaps, lightning might have split the trunk, leaving part of it jagged and dead. The two trunks may have become entangled with each other. Branches may have been blown in one direction so long that they bend that way permanently.
Types of Plants
Any woody plant whose parts are in proper proportion for dwarfing—and particularly, any that shows promise of interesting lines or “character”—is a good prospect for bonsai. The coniferous evergreens are most popular, because they hold their foliage all year, and because small-needled types are comparatively plentiful. Small-leaved deciduous trees can be at their most attractive best with spring’s budding new growth, summer’s airy foliage, fall’s brilliant color, or with the silhouette of a naked trunk in winter.
With flowering trees and shrubs the choice of varieties narrows even more. Large flowers with brilliant color and overpowering fragrance may destroy balance and proportion, and detract from the beauty of the plant itself. More delicate plants are more likely to enhance the picture. For obvious reasons, plants that bear fruits and berries in the proper scale are the hardest to find, and culturally the most difficult.
(For plants that are suitable for outdoor bonsai, see list at the end of Chapter 14.)
Sources
Bonsai becomes a reality faster, of course, when you start with a fairly mature plant. The most fruitful source is the selection of three-year-old trees and shrubs at your local nursery. Those growing in gallon-sized cans, or other containers, naturally accept pruning and transplanting with the least setback. They should be healthy plants, not overgrown or neglected, that have been regularly root-pruned and transplanted through their infancy. It is perfectly safe to buy them pot-bound if that condition has not persisted for several seasons, with the outer roots all dead as a result.
In selecting a specimen, first examine varieties that are by nature slow-growing and have leaves, or needles, in perfect scale. Be selective, pass up the symmetrical specimens that are best for ordinary landscaping purposes, and look for that one plant in a thousand, the one with interesting “character”—peculiarity of shape, irregular branches, low horizontal growth, stocky or twisted trunk. The most ideal plant has its largest branch near the base, and has no regular or opposite branches to be pruned away. Next to above-ground development in importance, is the below-ground root system. To be ideal, the root system should be a compact, shallow mass rather than one long taproot with a few offshoots. To make it even more ideal, the stoutest roots should be growing near the surface.
Younger, smaller bonsai plants are readily available from mail-order suppliers who specialize in them. Here, make your selection according to variety, and then train your plants as you grow them. But beware of cheap “bargain offers.” I speak with this advice because of the experience of some of my friends. They were too intrigued by Sunday-newspaper ads. Buy only from reliable growers who have invested time and care in developing healthy plants and, better yet, have labeled them true to name. For those who are more interested in the finished work of art than in the growing and creating of it, some florists and nurseries advertise mature, or nearly mature, bonsai. Again may I say, “Beware.” The supplier’s reliability is even more important.
Sometimes you can find precious bonsai-type shrubs or trees growing in the wild. Small seedlings of hemlock, ash, birch, maple, and some elms, if they are dug very carefully—and at just about any time of the year—can be used as miniature bonsai, or they can be planted in the garden for a few years until they are larger. Usually, the taproot has to be cut back rather severely to encourage the development of a spreading mass of smaller roots. Start your regular pruning as soon as the plant recovers from transplanting shock.
The larger native plants should be taken when they are dormant, in late fall or the earliest spring. In searching, look for those that have been naturally dwarfed and misshapen by misfortune. In digging, make sure the soil is so moist that much of it will cling to the roots. Keep the roots moist and well covered against drying sun and winds until the transplant is safely in the soil again. For any such wildlings, take along enough of the surrounding soil to fill the container into which they are going. This will make them feel at home in their new place in the garden bed.
Many growers now propagate their own bonsai plants; thus they can control shape, root-spread, line, and design from the very beginning. Almost all of the propagating methods outlined in Chapter 10 are useful here, some especially so. Cuttings of all kinds will produce stout-trunked plants much faster than seeds. Plants such as willow, holly, ginkgo, and ivy can be started from stems as thick as an inch or so in diameter. With cuttings you can have quantities of new plants from one parent, all with the same variegations or other characteristics.
Either ground or air layering can give you plants that are larger than those obtained from cuttings. By selecting a certain branch you can be surer of getting the characteristics and shape you want. If your bonsai is to be well balanced, select a well-proportioned branch with close twiggy growth. By layering you can also correct an unattractive bonsai, growing a new one from a plant that has become too tall and gangly, or one that has badly formed roots.
Grafting for bonsai plants is not widely practiced because too often it leaves a visible scar or some other sign of artificiality, and also because there is the danger of undesirable sprouts shooting up from the roots. Plants from a graft are generally weaker than cuttings or layers which have their own roots. If your plant happens to be a valuable one, you can often improve its shape by grafting on new branches where they will do the most good; or good branches can be grafted onto picturesque, gnarled roots. I have never made a serious effort to graft in such cases, but I have seen some good results from the work of other growers.
Growing bonsai plants from seed requires infinite patience—as a warning, the process takes years. But seedlings, once you have them going, and with the healthiest of root systems, will live indefinitely. Seeds of bonsai-type plants are available from several growers. Should they need special preparation, such as nicking or stratifying, the seed packets should say so.
When seedlings have several true leaves and are ready for transplanting, cut back the strong taproot (should there be one) by at least one-third. This will encourage root-branching. When potting seedlings, spread the side roots so they will develop evenly near the soil surface. Pruning and training can begin while the plants are still quite young. Plant the stem on a slant. Pinch new tip growth for development of side branches. Tie straight trunk stems to a bamboo cane, or perhaps just a sliver; or otherwise guide the young shrub, or tree, toward the lines you have in mind for its mature effect.