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.
BONSAI CONTAINERS
In no other art form is it more obvious that a subordinate element such as a container can make or mar the perfection of a picture. For instance, with a painting the frame can have small faults without lessening the impression of a masterpiece. But bonsai is so stark that a slight imperfection can become a glaring error. So, although the container is merely a supporting feature, it becomes only a little less important than the center of interest, the plant. It must harmonize with the plant, reflect and supplement its beauty, and not detract from its leading role.
Imported Japanese bonsai containers of the traditional type, now readily available, are usually shallow bowls or dishes of glazed (or unglazed) ceramic. They are never glazed on the inside and are usually sold in sets of three matched units of graduated size. Contemporary American artists and manufacturers are also turning out pans and trays made of dull metals, tile, and wood. The wood may be either of a natural finish or artistically weathered. For outdoor bonsai, wood must necessarily be treated for durability and weather resistance.
For indoor plantings, containers can very often be improvised. I’ve used bronze ash trays, wooden salad bowls, shapely plastic dishes (shallow), and odds and ends of pottery—anything of the right motif in which it is possible to bore, drill, or chip drainage holes on the bottom. Many of our modern ceramics are in complete harmony with bonsai. But you must have those drainage holes, otherwise your watering problems are compounded.
The ideal bonsai containers are seldom ornate; really they shouldn’t be. They should have the grace and elegance of “expensive simplicity,” which doesn’t mean they are expensive. They just look as though they were. Colors are subdued, not bright or showy. As a rule to follow, darker and somber shades are used for evergreens, lighter shades for flowering plants, the specific choice depending on the color of the bloom. In shape and form, bonsai containers are simple and graceful and are selected to set off the shape or lines of the plants. Erect trunks often take shallow, rectangular containers. Hanging or weeping lines call for round containers with more depth. Square or oval containers are used for extremely delicate, graceful subjects.
Container size, of course, depends on the plants themselves. As a general rule, the smallest and most shallow container that is culturally practical, and in good proportion, is the best. In true bonsai containers, diameters range from two to twenty-five inches; depths, from one to ten inches. The accepted rule for good proportions allows the plant to occupy 80 per cent of the picture, the container 20 per cent. Should you have very small plants the ratio is slightly changed—60 per cent for plant, 40 per cent for the container. However, these figures should not be considered as hard and fast, but as a guide when purchasing containers. Your eye may tell you what is better suited for your particular plant or shrub.