The following alphabetical list of plants includes trees and shrubs suitable for traditional bonsai. This is not intended to be a complete list. Specialty nurseries often have a wide selection of dwarf and semi-dwarf varieties of many of these species. Dwarf plants, however, do not always convey the same impression as their full size counterparts because the growth habit is quite different.

• Apricot: Prunus species
• Arborvitae: American, Thuja occidentalis; Oriental, Thuja orientalis
• Azalea: Hiryu, Rhododendron obtusum; Indica azalea, Rhododendron indicum Kurume; hybrids
• Beech: American, Fagus grandifolia; European, Fagus sylvatica
• Birch: White, Betula alba
• Boxwood: Buxus species
• Burningbush: Euonymus nana
• Cedar: Atlas, Cedrus atlantica; Deodara, Cedrus deodara
• Cherry: Prunus species
• Cotoneaster: Cotoneaster species
• Crabapple: Malus species
• Cryptomeria: Cryptomeria japonica and cultivars
• Cypress: Bald, Taxodium distichum; Dwarf hinoki, Chamaecyparis obtusa var. compacta
• Elm: American, Ulmus americana; Chinese, Ulmus parvifolia; Siberian, Ulmus pumila
• Fir: Abies species
• Firethorn: Pyracantha species
• Ginkgo: Ginkgo biloba
• Goldenrain: Koelreuteria paniculata
• Gum: Sweet, Liquidambar styraciflua
• Hawthorn: English, Crataegus oxycantha; Washington, Crataegus phaenopyrum
• Heather: Calluna vulgaris
• Hemlock: Canadian, Tsuga canadensis and cultivars
• Hornbeam: American, Carpinus caroliniana; Japanese, Carpinus japonica
• Ivy: Hedera helix and cultivars
• Jasmine: Winter, Jasminum nudiflorum
• Juniper: Juniperus species and cultivars
• Locust: Black, Robinia pseudoacacia
• Maple: Amur, Acer ginnala; Hedge, Acer campestre; Trident, Acer buergerianum
• Oak: English, Quercus robur; Pin, Quercus palustris; Scarlet, Quercus coccinea; White, Quercus alba
• Peach: Prunus species
• Pine: Bristlecone, Pinus aristata; Japanese white, Pinus parviflora; Japanese black, Pinus
• thunbergi; Mugo, Pinus mughus; Swiss stone, Pinus cembra; White, Pinus strobus
• Plum: Prunus species
• Pomegranate: Dwarf, Punica granatum nana
• Quince: Japanese, Chaenomeles japonica
• Snowbell: Japanese, Styrax japonica
• Spruce: Picea species and cultivars
• Willow: Weeping, Salix blanda
• Wisteria: Japanese, Wisteria floribunda
• Yew: Taxus species and cultivars
• Zelkova: Graybark elm, Zelkova serrata

House Plants

American gardeners have taken bonsai concepts and have applied them to houseplants. By combining traditional procedures for handling houseplants with bonsai concepts of design, growers have created different bonsai styles. The following alphabetical list consists of woody plants (native to the tropics and subtropics of the world) that have been grown as indoor bonsai. These plants can be obtained from either local or specialized nurseries.

• Acacia: Acacia Baileyana
• Aralia: Polyscias balfouriana, Polyscias fruticosa, Polyscias guilfoylei
• Bird’s Eye Bush: Ochna multiflora
• Camellia: Camellia japonica, Camellia sasanqua
• Cape-Jasmine: Gardenia jasminoides radicans, Gardenia jasminoides
• Citrus: Citrus species (calamondin, kumquat, lemon, lime, orange, and tangerine)
• Cherry: Surinam, Eugenia uniflora
• Cypress: Arizona, Cupressus arizonica; Monterey, Cupressus macrocarpa
• Fig: Mistletoe, Ficus diversifolia
• Herb: Elfin, Cuphea hyssopifolia
• Hibiscus: Hibiscus rosa-sinensis Cooperi
• Holly: Miniature, Malpighia coccigera
• Jacaranda: Jacaranda acutifolia
• Jade: Crassula species
• Jasmine: Jasminum parkeri; Orange, Murraea exotica; Star, Trachelospermum jasminoides
• Laurel: Indian, Ficus retusa
• Myrtle: Classic, Myrtus communis
• Oak: Cork, Quercus suber; Indoor, Nicodemia diversifolia; Silk, Grevillea robusta
• Orchid Tree: Bauhinia variegata
• Oxera pulchella
• Pepper Tree: California, Schinus molle
• Pistachio: Chinese, Pistacia chinensis
• Plum: Natal, Carissa grandiflora
• Poinciana: Royal, Delonix regia
• Pomegranate: Dwarf, Punica granatum nana
• Powderpuff Tree: Calliandra surinamensis
• Serissa foetida
• Shower Tree: Cassia eremophila

You can also obtain books that supply information about growing plants indoors from your local library.

Obtaining Plants

Figure 11. A group planting in any of the bonsai styles makes use of only one species of tree. A Banyan (Ficus neriifolia ‘Regularis’) is shown here.

There are many ways to obtain bonsai. At the beginning it is best to work with the more common plants. Most are obtainable at local nurseries. Plants that are native to the area where you live often make fine subjects for bonsai. But make sure these plants meet the bonsai requirements of size, leaf, trunk, and scale (Figure 11).

Some old favorites grown as bonsai because of their classical good looks are Sargent juniper (Juniperus chinensis Sargentii); Japanese black pine (Pinus thunbergii); wisteria (Wisteria floribunda, Wisteria sinensis); flowering cherries (Prunus subhirtella, Prunus yedoensis); and gray bark elm (Zelkova serrata).

Among the plants recommended for the beginner are:

• Firethorn (Pyracantha coccinea or Pyracantha fortuneana), which is an evergreen with small leaves;
• Cotoneaster (Cotoneaster dammeri), which has characteristics similar to those of firethorn;
• Dwarf pomegranate (Punica granatum nana), which is deciduous, and has tiny green leaves; and
• Juniper (Juniperus scopulorum or Juniperus virginiana), which is a hardy evergreen with heavy foliage that takes well to pruning.

In addition to nursery stock, plants for bonsai can be collected from the wild or propagated from plants in your garden (See discussion of propagation). Growers can now purchase mature bonsai created in this country; these plants have recently become available at selected nurseries. Mature bonsai plants also can be imported from Japan, but only deciduous varieties ship well.

Collecting Plants from the Wild

The job of finding plants in the wild that adapt well to bonsai is difficult for the beginner. Traveling in wild terrain where such specimens are found can be hazardous. Also, at least a year must pass before a plant collected this way can be containerized, and much care is necessary to insure survival during this period. Wild plants, however, often look older than they actually are and make handsome specimens.

The best time for collecting plants in the wild is during March and April, when new growth or leaves have not yet begun to sprout. Here, the collector must recognize when the wild plant is in its dormant period.

On a collecting trip the following items will be helpful: a small collapsible shovel; polyethylene sheeting and string for wrapping rootballs; sphagnum moss for packing around the rootball; a container of water for wetting leaves and rootball; and a small crowbar forgetting roots out of rocks.

Remember the following points when taking plants from the wild:

1. Get permission to dig from the owner of the property.
2. Do not randomly dig wild plants. Make sure that the plant you are removing is not on your State conservation list. Remember that nothing can be removed from national parks and similarly conserved areas.
3. When digging the plant you want, try not to injure the taproots. Get as much soil around the roots as possible. Older trees will require greater care and a slower training schedule.
4. After you cover the roots and soil with wet sphagnum, wrap the rootball in polyethylene film. Wet the branches with water frequently.
5. At home, unwrap the rootball carefully. (It is not necessary to unwrap the rootball if it is wrapped in burlap.) Plant the tree in loose garden soil in a location that is protected from the sun and wind.
6. Water, and examine the roots of the new plant for several months. Feed the plant sparingly.
7. After at least 1 year, the plant can be dug up and placed in a container. (Large trees may have to go into a succession of smaller containers before they are ready.) Trim the roots around the base carefully so the plant will fit into its container.
8. If shaping is necessary when potting a collected tree, prune the branches lightly.
9. Two years after the plant has been collected from the wild, start it on a regular training program.

Importing Mature Plants

If you are going to import bonsai trees from Japan, it is best to do so during their dormant period. Such
plants are subject to severe fumigation before they are allowed to enter this country and thus are likely to be
harmed by fumigation.

Bonsai plants are now available that have been trained in the United States. These plants have the advantage
of being acclimated to various areas of the country.

Nursery Plants

The easiest and best method for the beginner to obtain bonsai is to buy nursery stock and develop his own. These plants come in 1- and 5-gallon cans and their root systems have become adapted to cramped conditions. Buy only young, healthy plants when purchasing nursery stock. When searching for potential bonsai among nursery stock, do the following:

• Look for plants that are well rooted and well branched. The plant must be able to withstand severe initial pruning.
• Inspect the overall plant and then push back the foliage and examine the base from all sides. See if the foliage is full enough to be shaped into an interesting bonsai. Check to see if branches are where you will need them.
• Do not purchase a plant that cannot be easily transplanted to a pot.

Do not thin the root system excessively all at once when placing the plant in a smaller container. By thinning the roots gradually and reducing the root system, safely and over a period of years, you will not damage the plant. If you prune and shape first and neglect thinning the roots, some plants may die.

Bonsai can be classified into five basic styles: formal upright, informal upright, slanting, cascade, and semi-cascade. These classifications are based on the overall shape of the tree and how much the trunk slants away from an imaginary vertical axis.

The numerous Japanese bonsai styles are principally variations of these five basic styles. The styles given in this bulletin apply to trees with single trunks. The single trunk style is the basic design that is simplest to shape because the one trunk determines the overall composition.

Formal Upright

Figure 2. The formal upright style features a straight trunk, and a bottom branch that is lower and extends further from the trunk than its opposite. This specimen is a Mugho pine (Pinus mugo "Mugo").

Figure 1. Note the off-center placement of this redwood (Sequoia sempervirens) in its oval container. This tree was trained in the formal upright style, which is considered the easiest for the novice bonsai grower.

The formal upright style has classic proportions and is the basis of all bonsai. It is the easiest for a beginner to develop
because it requires the least experimentation, avoids the problem of selective pruning, and should almost immediately become a display able bonsai.

In this style, the form is conical or sometimes rounded and the tree has an erect leader and horizontal branches. One of the branches is lower and extends a little farther from the trunk than the others (Figure 1). Also, the lowest two branches are trained to come forward on the front side of the tree, one slightly higher than the other. The third branch of this style extends out in the back of the tree at a level between the two side branches to give the plant depth (Figure 2).

Plants in the formal upright style look best in oval or rectangular containers. Do not center the plant when placing it in
the container. Plant it about a third of the distance from one end.

In choosing a nursery plant for this style, make sure the trunk rises from the ground in a fairly straight line. The trunk should be straight and not fork or branch out for the total height of the tree. Trim off the small branches or twigs that are too close to the base and near the main stem. These branches detract from the overall composition.

Informal Upright

Figure 3. This trident maple (Acer buergerianum) bonsai, is trained in the informal upright style. The style is similar in branch placement to the formal upright style, but differs because of the angularity of the trunk.

Figure 4. The trunk in the informal upright style bends slightly to the front. This specimen is 32 years old, a San Jose juniper (Juniperus san jose) in training since it was a seedling.

The informal upright style has much the same branch arrangement as the formal upright style, but the top — instead of being erect as in the formal upright style — bends slightly to the front. This bend makes the tree’s branches appear to be in motion and enhances the look of informality (Figures 3 and 4).

The informal upright style looks best in an oval or rectangular container. It should be planted, not in the center of the container, but a third of the distance form one end.

Many nursery trees are naturally slanted. This makes them well suited to the informal upright style. Check the tree’s slant by looking down at the trunk from above — from this angle the top should slant to the front. If this view is not attractive, you may move the root ball to slant the tree in another direction.

If you choose a vertical tree at the nursery, and want to train it in the informal upright style, simply tilt the plant when potting it. When you do this, trim the branches and foliage so they are scaled to the size of the tree.

Slanting

Figure 5. This common juniper (Juniperus communis), estimated to be about 80 years old, was collected in 1979, and has been trained in the slanting style of bonsai. In this style, the lowest branch spreads in the opposite direction to the slant of the tree.

Figure 6. In the slanting style the trunk has a more acute angle than in the informal upright style. This specimen is a Lantana, salvaged from a construction sight in 1959.

In the slanting style, the trunk has a more acute angle than in the previous styles. The lowest branch should spread in the direction opposite to that in which the tree slants. The top of the tree is bent slightly toward the front (Figures 5 and 6). The lower branches are arranged in groups of three, starting about one-third the way up the trunk.

Slanting trees in nature are called “leaners” — trees that have been forced by the wind and gravity into nonvertical growth. The attitude of the slanting style falls between the upright and cascade styles. This style looks best planted in the center of a round or square container.

Cascade

Figure 7. Elephant bush (Portulacaria afra), trained in the cascade style, has a characteristic leader, which descends below the bottom edge of the container. A cascaded bonsai usually looks best in a round or hexagonal container.

Figure 8. The cascade style of bonsai represents a natural tree growing down the face of an embankment. This specimen is a three-leaf Akebia (Akebia trifoliate) estimated to be about 30 years old.

In the cascade style the trunk starts by growing upward from the soil, then turns downward abruptly, and reaches a point below the bottom edge of the container. For this reason, the container should be placed on the edge of the table, or on a small stand (Figures 7 and 8).

The cascade style has most of its foliage below the soil surface. This style is representative of a natural tree that is growing down the face of an embankment.

Training a tree in the cascade style takes longer than in the slanting style. Choose a low-growing species instead of forcing a tree that normally grows upright into an unnatural form. Bend the whole tree forward so one back branch is vertical and the side branches fall naturally.

A cascaded planting usually looks best in a round or hexagonal container that is higher than it is wide. The tree should be planted off-center from the cascading side.

Semi-Cascade

Figure 9. This Shimpaku juniper (Juniperus chinensis ‘Sargentii’ ‘Shimpaku’) in a hexagonal container was trained in the semi-cascade style. Prostrate junipers and flowering plants are well adapted to cascade and semi-cascade styles.

Figure 10. The semi-cascade style has a curving trunk that does not reach the bottom of the container as it does in the cascade style. This example is a little leaf Cotoneaster (Cotoneaster microphylla).

The semi-cascade style has a trunk that is allowed to grow straight for a certain distance, and then is cascaded down at a less abrupt angle than in the cascade style (Figures 9 and 10). The cascading branches are thought of as the front of the tree, and the back branches are trained closer to the trunk than in the other styles. The semi-cascade should not reach below the bottom of the container, but should go below the level of the soil surface.

Plants that are well adapted to the cascade and semi-cascade styles are prostrate junipers, and flowering plants such as chrysanthemums, wisteria, willows, and star jasmine.

Before potting a tree for bonsai in any of the five styles, keep in mind the image of how the tree will stand in the container. Don’t plant a tree one way, and then uproot it to make a change. Keep your overall theme in mind when planting bonsai. Upright trees should have a stabilized look in the container; slanted and cascaded styles often have their upper root surfaces exposed to imitate plants that grow this way in nature.

No matter what style you choose — whether single trunk specimens or groups of trees from single roots — everything depends on your selection of plant material, and your ability to visualize the bonsai’s final form.

Bonsai with red leaves

Not all plants are equally effective as bonsai. To produce a realistic illusion of a mature tree, look for plants with the following characteristics:

• Small leaves or needles.
• Short internodes, or distances between leaves.
• Attractive bark or roots.
• Branching characteristics for good twig forms.

All parts of the ideal bonsai — trunk, branches, twigs, leaves, flowers, fruits, buds, roots — should be in perfect scale with the size of the tree. Plants used for bonsai should have small leaves, or leaves that become small under bonsai culture. Plants with overly large leaves, such as the avocado, will look out of proportion if chosen for bonsai. Sycamores also develop leaves that are too large. Certain species of both maple and oak trees usually respond well to bonsai culture and develop leaves that are in proportion.

Among the plants with small leaves and needles are spruce, pine, zelkova, pomegranate, and certain oaks
and maples.

Plants chosen for bonsai should have attractive bark, and the trunk must give the illusion of maturity. The trunk should have girth, but must remain in proportion to the entire tree. The trunk should taper gradually toward the top of the tree. Sometimes one or two of the main branches must be shortened to emphasize the vertical line of the trunk and give the trunk a balanced appearance.

To give the appearance of age, the upper one-third of the root structure of a mature bonsai is often exposed. This is especially effective if the roots have good girth and form. Twisted and tangled roots should be straightened before potting or repotting a tree to achieve an aged appearance. Bonsai from nursery stock, and trees collected from the wild, should have a root system that will — when exposed — add to the appearance of the finished bonsai.

Plants have a “best profile” just as people do. Decide on the front of the tree at the very beginning, because planting and shaping are done with the front of the tree in mind. However, you may change your ideas about the plants ultimate shape as you clip and prune.

The front of the bonsai should offer a good view of the main trunk, which must be clearly visible from the base to the first branch, typically about one-third the way up. Everywhere on the tree, but mostly from the front, the branches should look balanced and appear to be floating in space; they should not appear lopsided or top-heavy. The branches should not be opposite one another with their lines cutting horizontally across the trunk. The branches give the bonsai the dimension and establish the tree’s basic form.

A bonsai should have a harmonious arrangement of branches without unsightly gaps. Flaws can be spotted by looking down on a bonsai. Upper branches should not overshadow lower branches.

Before deciding on the shape of your bonsai, study the tree carefully, and take into account the natural form of the species. Observe the way mature trees of the same kind grow in their natural setting to achieve an impression of age and reality.

Decide on the final shape and size of your bonsai before starting. Make a rough sketch of what you wish to create and use it as a guide.

Bonsai Trident Maple

Bonsai are miniature trees grown in pots. The aim of bonsai culture is to develop a tiny tree that has all the elements of a large tree growing in a natural setting. This look is achieved, principally, by branch and root pruning and shaping, but other factors are also important. The texture of the trunk, its look of age, the moss and the under plantings in the container — all contribute to the illusion of a miniature tree as it is seen in nature.

A presentable bonsai can be created in a few seasons. Cultivating these miniature potted trees is both an intriguing hobby, and a means of adapting a wide range of plants to specialized and decorative uses. Bonsai require daily watering during their growing season, and, because the plants are rooted in shallow pots, careful pruning.

Bonsai are kept outdoors most of the year, but — from time to time — these miniaturized versions of nature are brought indoors for display. Only certain tropical trees, shrubs, and vines can be continually kept indoors full time as bonsai.

Bonsai, as an art form, stems from ancient oriental culture. It originated in China and was developed by the Japanese. In the 13th century, the Japanese collected and potted wild trees that had been dwarfed by nature. These naturally formed miniatures were the first bonsai.

When demand for the small trees outstripped the supply, Japanese gardeners began to train bonsai from native trees. They shaped the trees to give them the illusion of age and naturalness. Over the years, the Japanese devised standards of shape and form, which gradually began the classic bonsai styles.

American bonsai are much freer in concept and style than Japanese bonsai. American bonsai growers have recognized that the horticultural and aesthetic rules are important, but are specifically aimed at Japanese culture. Because of this, Americans have taken oriental styles and applied them to plants never grown by the Japanese.