Question: I saw some amazing bonsai plants at a crafts show this past weekend. Can any tree or plant be grown into a bonsai or are they special varieties? Jana, Eugene, Oregon
Answer: Jana, Bonsai, or dwarf tree culture, is a hobby enthralling in its possibilities. It offers the opportunity to play with nature in a small space. With it you can bring the striking beauty of a windswept Monterey cypress, a Colorado pine or a landscape of white birches into your living room, whether it is in a city apartment or a country home. The Japanese word “bonsai” literally means “dwarf tree or potted dwarf tree”. It differs from an ordinary potted plant in that it is developed to create an aesthetic piece of scenery, texture or floral design. Bonsai culture emphasizes the individuality of each plant; this is the key to the art of bringing up a tree in a pot.
Native Plant Possibilities
Our native plants offer a full reach of interesting shapes, colors and textures for dwarf culture. The rough bark of bur oak, the white bark of birch, the gnarled and grooved trunk of cypress, the twisted trunk of juniper and the straight trunk of white pine are picturesque. Other good materials with which to work are flowering fruit trees and weeping willows. Selection is made according, to the effect to be produced; but slow-growing types of plants are best because they make the task of trimming easier.
Although it is impossible to make the branches of a bonsai grow in correct proportion to the trunk of a tree as it might appear in nature, the branches and trunk must, nevertheless harmonize. The branches of the bur oak quickly assume the rough texture of the trunk; the twigs of the pinon pine become gnarled in a short time.
Leaves of dwarfed material, however, are not appreciably reduced in size with the rest of the plant. A 2-inch needle is the largest size which will be harmonious on a dwarfed evergreen tree. Because leaves on deciduous plants can be reduced somewhat by cultivation, the largest desirable normal leaf size is 4 inches.
Nursery Grown – Beginners Best Bet
Many of the bonsai growers in the past have made a cult of collecting dwarfed material. They went through complicated rituals before starting on their journeys in search of just the right material, in the belief that unless these rituals were strictly followed their hunting efforts would not be rewarded. This selection of wild materials already worked into interesting shapes by nature often saved years of work and was worth the effort.
The beginner, however, should be wary of collected wild plants. Even with experts in this field, a mortality of 30 per cent or more is not uncommon. The beginner, just learning how to grow plants, would have better luck with nursery-grown seedlings or cuttings a few years old. A nursery-grown plant with a properly developed root system will develop faster and more surely than its wild counterpart with meager roots.
Pots – The Bonsai Picture Frame
Pots are to bonsai culture what frames are to pictures. Once the plant has been decided upon, the choice of a pot comes next. There must be harmony of the whole. The pot must accentuate, not detract from, the beauty and elegance of the plant. A new pot would not fit an old gnarled tree. A deep pot would not fit a squat, spreading tree. A brightly colored pot would draw attention away from the subject of interest. Sobriety and subdued effects are essential here.
For healthy plants unglazed pots or rough pots baked at a temperature of about 1000 degrees are usually recommended. Trays or flat stones have been used by experts for dwarf tree culture. But almost any object can be used as long as it accomplishes the job of acting as a “frame” for the plants and as a receptacle for the roots. Most bonsai plants eventually find their way into shallow tray-pots, 4 to 6 inches deep and from 24 to 30 inches long.
Bonsai Soil Extreme Importance
Soil – because there is so little of it in bonsai culture – is of extreme importance. It must be able to retain moisture, but at the same time allow air to circulate. There requirements demand a granular soil with a large amount of humus. A recommended average mixture is a soil containing five parts of a coarse granite sand with grains up to 1 millimeter in diameter, three parts loam and two parts humus such as peatmoss or well-rotted compost with little or no manure or commercial fertilizer. In bonsai culture the roots are greatly restricted so high concentrations of minerals would be harmful to the plant.
Planting – Careful and Methodical
Planting and transplanting must be carefully and methodically done. In nature, roots normally grow unrestricted in all directions but in the limits of a pot this is not possible. In a shallow bonsai pot, the roots of a pine tree often form a mound above the level of the pot; the shallow roots of a silver maple fan out to form a solid mat on the surface of the soil.
The time for transplanting depends on each individual plant. Generally speaking, transplanting should take place each spring as the buds begin to swell. Satisfactory transplanting can be done in the fall if necessary. If undertaken at that time, it should be done just as leaves start to drop and well before heavy frost so that the plant has time to recover from the shock of transplanting before winter sets in.
Drainge A Must
Bonsai pots must have drainage holes in the bottom – about one for each half square foot. Before the soil is added to the pot, the drainage holes must be covered, usually with broken pieces of pots. The bottom of the pot is then covered with about 34 inch of pea-sized gravel or charcoal and this in turn is covered with a thinner layer of smaller gravel or charcoal. This done, the pot is ready to receive the plant.
If it is a young seedling, the roots are simply spread out and the future bonsai is planted as described below. If the plant is older and pot-bound, or is undergoing its annual transplanting, about two-thirds of the old soil is removed by washing or by slowly and carefully prying it away from the roots so the delicate root hairs are not injured. Then the roots are pruned freely.
Root Pruning With Top in Mind
In root pruning, it is necessary to work with the top of the plant in mind. The more roots the plant has, the more growth will be produced above ground. In the case of the old bonsai in which little growth is desired, old root tips or possibly whole roots of little vitality are cut off, being careful not to disturb fibrous lips already formed.
In the case of a young bonsai in which growth is vigorous. pruning off the heavy roots back to the crown will help reduce too vigorous top growth. In any case, do not cut off all growing tips at one transplanting. This would result in a choked mass around the crown and would encourage decay and disease. The root ball should always have room at the center for new root development as the old coarse roots lose vitality. When the plant is properly trimmed, the root system should roughly correspond to the branch structure, on a fore-shortened scale.
After the roots are trimmed, the plant is placed in the pot which has been prepared as described above. The pot is filled to the proper level with the special soil mixture which is tamped carefully around the roots as it is put in. The plant is set at the proper depth for beauty and health. Topsoil should be screened to eliminate lumps which would permit air pockets to develop around the roots.
After the plant is repotted and the soil carefully firmed around its roots, it should be watered until moisture runs out of the drainage holes. If the plant becomes unsteady in the watering process, it should be braced in position until it is re-established.
Exposure To The Elements
The bonsai should be placed where it will get mild exposure to the elements. Since it must be allowed to go through its normal quiescent or dormant stage – arrested growth in the case of evergreens, dropping of foliage in the case of deciduous material – continued confinement to the house or greenhouse might produce disastrous results. Plants in pots will generally stand exposure to conditions prevalent in the next warmer climatic zone in which they are normally hardy. They should also be protected from strong winds and heavy snows.
Logically Watering Your Bonsai
Watering must be done with logical care. The plant should be watered before the soil gets dry and hard. During the growing season this may be twice a day, morning and evening; during the dormant period, only occasionally. Sprinkling the foliage will help keep the plant healthy and clean.
The bonsai lives a life of austerity. The strongest fertilizer that should be used is bonemeal or wood ashes. This, applied once a year about midway between transplantings, should be enough. The plant will respond to feeding just as any normal plant, except that the response will be much more pronounced and quick because of the lack of soil.
Pruning For Perfect Form
Pruning is essential to keep the bonsai in perfect form, just as pruning a fruit tree is essential to keep it healthy and bearing. Evergreens, as well as deciduous plants, should have from two-thirds to three-fourths of their new growing tips picked off. The subsequent secondary growth which appears must also be picked off. The choice of which tips to retain depends on the shape one wishes the tree to assume.
Pruning and training are the art of bonsai culture. The initiative and imagination of the grower come into play here. To know which branches to cut off – carefully, so as to leave no ugly scars – and which twigs or branches to bend into desired curves or positions to complete the picture, is the satisfying game which the grower is constantly playing.
Here is an art which has been practiced in Japan for centuries. It has reached a peak of perfection and specialization impossible to describe in words. But bonsai or dwarf tree culture is within the reach of any gardener who likes to grow plants. It is not an art controlled by a few highly trained specialists. It is a hobby, inexpensive to develop and enthralling in its possibilities.
by G Radenburg
