Date: Sun, 2 May 93 13:42:25 PDT
From: "Richard K. Nordin" 

I was sorting through my old bonsai catalogs and I stumbled across
this: "Growing Bonsai", a bulletin of the United States Department of
Agriculture. Noticing that it was delightfully free of copyright, I
decided this would make a good "text" for the ongoing bonsai class I
am conducting.

It is not great information. It is short, and somewhat provincial, but
the price is right. It is good basic information.

This will let me skim a lot of details, and just concentrate on the
fun part--coaching, mentoring, exhorting, encouraging, or pushing you
into attempting your own first bonsai.

I'll keep on with the classes. And, hey, feel free to ask questions in
the context of the class, as long as you are a beginner. I would
prefer that more advanced questions go to the general audience, so I
don't feel compelled to answer them, and so that we don't scare anyone
off. I have gotten some email questions that would have been fine
fodder for posting. I may summarize those answers for the class
anyway, since I just hate throwing away good general-purpose
keystrokes. But if you are wondering, so, too, probably are some of
your compatriots, so post the questions.

Disclaimer: if I haven't made it clear already, I am not a bonsai
expert (but, feel free to worship me, anyway :). I dabble, but my
depth is limited. Take none of my words as gospel.

Upcoming is the USDA bulletin "Growing Bonsai" in 4 parts.

[End of Growing Bonsai Part 0 of 4]

[Growing Bonsai Part 1 of 4]

GROWING BONSAI

United States Department of Agriculture

Home and Garden Bulletin No. 206

Issued August 1973

Superintendent of Documents
U.S. Government Printing Office
Washington D.C. 20402
Stock No. 0100-02772

Prepared by Henry M. Cathey
Plant Genetics and Germplasm Institute
Northeastern Region
Agricultural Research Service

CONTENTS

Introduction
Principles of bonsai
Choosing a style
Bonsai guide
Obtaining plants
Shaping your bonsai
Containers for bonsai
Potting
Repotting
Growth media
Seasonal care
Propagating your own bonsai
Displaying your bonsai

INTRODUCTION

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
underplantings 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. Therefore, the rigid procedures and names used by the
Japanese are not used in this bulletin.

PRINCIPLES OF BONSAI

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.

CHOOSING A STYLE

Bonsai can be classified into five basic styles: formal upright,
informal upright, slanting, cascade, and semicascade. These
classifications are based on the overall shape of the tree and how
much the trunk slants away from an imaginary vertical axis. (See
figs. 4 and 6.)

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.

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 displayable 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. (See fig.  1.)

[Figure 1 (Photograph unavailable. Caption:)--Note the off-center
placement of this mugho pine in its rectangular container. This tree was
trained in the formal upright style.]

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. (See fig. 2.)

[Figure 2 (Drawing unavailable. Caption:)--The formal upright style is
considered the easiest for the novice bonsai grower. This style
features a straight trunk, and a bottom branch that is lower and
extends further from the trunk than its opposite.]

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.

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. (See figs. 3 and 4.)

[Figure 3 (Photograph unavailable. Caption:)--Flowering plum bonsai,
trained in the informal upright style, is set on a rock; this setting
enhances the illusion of a tree growing in the wild.]

[Figure 4 (Drawing unavailable. Caption:)--The trunk in the informal
upright style bends slightly to the front. This bend helps to give the
style of informality.]

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 rootball 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.

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.

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. (See figs. 5 and 6.)

[Figure 5 (Photograph unavailable. Caption:)--Lodgepole pine was 67
years old when it was collected from the Sierra Nevada mountains of
California; it was trained in the slanting style of bonsai.]

[Figure 6 (Drawing unavailable. Caption:)--In the slanting style the
trunk has a more acute angle than in the informal upright style. The
lowest branch spreads in the opposite direction to that in which the
tree slants.]

The lower branches are arranged in groups of three, staring 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.

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. (See figs. 7 and 8.)

[Figure 7 (Photograph unavailable. Caption:)--Firethorn bonsai,
trained in the cascade style, has a characteristic leader which
descends below the bottom edge of the container.]

[Figure 8 (Drawing unavailable. Caption:)--The cascade style of bonsai
represents a natural tree growing down the face of an embankment. A
cascaded planting usually looks best in a round or hexagonal container.]

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.

The semicascade 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. (See figs. 9 and 10.)

[Figure 9 (Photograph unavailable. Caption:)--Cotoneaster in round
container was trained in the semicascade style.]

[Figure 10 (Drawing unavailable. Caption:)--The semicascade style has a
curving trunk that does not reach the bottom of the container as in the
cascade style. Prostrate junipers and flowering plants are well adapted
to both of these styles.]

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 semicascade 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 semicascade 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.

[End of Growing Bonsai Part 1 of 4]

[Growing Bonsai Part 2 of 4]

BONSAI GUIDE

Trees and Shrubs

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
semidwarf 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, Rhododendron hybrids

BEECH:
American, Fagus grandifolia
European, Fagus sylvatica

BIRCH:
White, Betula alba

BOX:
Buxus species

BURNINGBUSH:
Euonymus nana

CEDAR:
Atlas, Cedrus atlantica
Deodar, 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
house plants. By combining traditional procedures for handling house
plants 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

[Information about USDA house plant bulletin deleted, due to age.]

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

[Information about bonsai publications deleted, due to age.]

OBTAINING THE PLANTS

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 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. (See fig. 11.)

[Figure 11 (Photograph unavailable. Caption:)--A group planting in any
of the bonsai styles makes use of only one species of tree. Cryptomeria
is shown here.]

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 graybark 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 characteristics similar
to those of firethorn; the 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 propogated from plants in your garden. (See discussion of
propogation [below].)

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 for getting
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 moths. 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.

To find out which trees can be imported, check with the Plant Protection
and Quarantine Programs, Animal and Plant Health Inspection Service,
U.S. Department of Agriculture, Hyattsville, MD 20782.

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.

The nursery plant

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.

[End of Growing Bonsai Part 2 of 4]

[Growing Bonsai Part 3 of 4]

SHAPING YOUR BONSAI

Strive for flowing form when shaping bonsai. Visualize the overall theme
and try to get a three-dimensional effect. Remember to select the front,
back, and sides of your bonsai before pruning, and don't forget to
examine the roots that will influence the growth of these areas.

For overall design. the "Rule of Thirds" is a simple concept to use as a
basis for obtaining a pleasing form for your bonsai. The "Rule of
Thirds" (see fig 12.) assures you of getting the proper division of
space. In this aid to design, the total space is divided into thirds--
both horizontally and vertically.

[Figure 12 (Drawing unavailable. Caption:)--The "Rule of Thirds" is a
useful design aid when planning the overall form of your bonsai. The
total space of plant and container is divided into thirds, both
horizontally and vertically.]

Use your pruning shears judiciously to make changes that benefit your
bonsai. Fine adjustments are made by wiring and bending and thinning
(removal of branches). Remember that a badly designed bonsai will not
grow well.

Before shaping a plant into a bonsai, decide whether the best attitude
of the tree is upright, slanted, cascaded, or semicascaded. Examine the
general form of the tree and note whether it is straight or twisted.
Match the potential of a tree to the style that fits it best. Decide
whether the base will rise from the soil level or whether you will
expose bare roots.

Three basic operations are necessary to establish the basic form in
bonsai culture:pruning, nipping and wiring.

You will need the following basic tools: a pair of sharp hook-and-blade
pruning shears; a garden trowel; blunt sticks; a pair of sturdy wire
cutters; copper wire of various lengths; and a sprinkling can. Also
useful are scissors for trimming leaves, tweezers for nipping, and
brushes for cleaning top soil.

Pruning

Nursery plants are often overgrown and need much pruning to establish
their best form. Through pruning, you control growth and form by
removing excess foliage and ugly limbs.

Some points to remember when pruning are:

-Make all cuts above a bud, a side branch or a main fork of the tree.
Remove all buds except those on the outside of the trunk to force the
growth outward and upward.

-Leave stubs flush with the stem; long stubs serve as an entry for
insects.

-Avoid cutting back so far that you weaken the main branches.

When pruning, keep branches growing toward an open space instead of
toward each other or the trunk. Do not shear bonsai as you would cut a
hedge; shearing makes the plant look artificial.

After deciding on the foliage form for your bonsai, remove all crossed
branches until the tree takes on the form you selected.

If you want to slant a tree that has been growing in an upright position
and insure that branches take a natural shape, prune it in an upright
attitude, and then tip it to where it should be and work on it that way.

Next, cut back new growth and thin out excess branches. When pruning an
upright style, remove unneeded side branches and leave the center ones
that will fill out as they grow.

Space out your pruning schedule, even if the plant has heavy foliage.
Plants must have a certain number of leaves for photosynthesis.

Protect pruning scars when removing heavy wood from thick branches or
the trunk. Cut the wood as close to the trunk as possible, pare the
stump flush, then scoop it out with a chisel, making a shallow wound
that will heal without looking unsightly. Treat these wounds with
grafting compound and they will be unnoticeable after healing. Several
years must pass before the bark will grow over these cut surfaces and
replace the scar tissue.

Nipping

A tree usually requires one heavy pruning in its life to establish its
basic form. After this initial pruning, shaping is done by nipping.
Nipping, or pinching back, is done to shape and develop the trunk and to
control the overall size of the plant. Nipping controls new growth
before it becomes so dense that it must be pruned.

A twiggy plant can be made more dense when it is nipped. When all
terminal buds on a branch have been pinched, several side shoots
develop. In this way growth is stimulated. This will give the plant a
bushier appearance.

Nipping is done not only to shape a plant but also to develop more
luxuriant foliage. As the new growth tips show up, nip them with your
fingers, twisting rather than pulling. Also nip off tiny spurs that
appear on the trunk or along heavy branches. These may develop into
unsightly suckers that will leave scars when removed. Do not overdo this
removal; be careful not to damage the foliage you leave on the plant.

After the top of a bonsai is pruned, trim the roots. Try to keep all
fibrous roots and maintain a balance, if possible, of one branch for one
root. Remove any roots that were damaged in digging. Leave the surface
root system intact and make it appear as if the roots cling to the soil
surface. Prune roots with sharp, sloping cuts to avoid damaging them.

Wiring

The wiring and bending of branches that give bonsai its shape is unique
to the art. Wiring is done after pruning when the tree has been thinned
to essential branches.

Copper wire is usually used for shaping bonsai because it is flexible.
The sizes of copper wire that are best for bonsai are: 10, 12, 14, 16,
and 18. (No. 8 wire is heavy and should be used only for the trunk.)
Wire as light as No. 16 should be used for very thin branches, and for
tying rather than bending.

Wire evergreen trees only during their dormant period when the branches
can be shaped without damaging growth. Wire deciduous trees only during
their growing season.

The day before you wire a plant do not water it; this will make the
branches more flexible. Once a branch has taken on its trained form,
remove the wire, straighten out its twists, and flatten it with a mallet
for reuse.

Wiring and shaping should begin at the lowest point of the tree, working
upward. Do the following when wiring:

1. Anchor the end of the wire at the base of the tree before winding it.
Push the end of the wire deep into the soil.

2. Wire from the trunk to the main branch. Use a foam pad under the wire
to prevent damaging the bark. Keep the turns about 1/4-inch apart and
spiral upward at a 45-degree angle. Do not wire too tightly, and do not
damage the leaves or stems.

One length of wire can serve for two branches by anchoring the center of
the wire at the trunk.

After wiring, the plant is shaped or bent by hand. The trunk and main
branches are gradually bent in the planned direction. Never try to
straighten a branch that has been bent; this may split the bark.

Branches sometimes snap, even when carefully wired and bent. If the
branch is not completely broken, rejoin the broken ends, and wind some
garden tape around the break. These fractures often heal quickly. If a
branch snaps off, prune back cleanly at the first side branch.

Wire should be kept on the plant for not more than 1 year. Remove the
wire before the bark becomes constricted; ridges will form if the wire
is left on too long. When removing a wire, start at the outermost end of
the branches, and take care not to harm leaves, twigs, or bark.

CONTAINERS FOR BONSAI

Most plant material for bonsai has long roots that will not fit into a
bonsai container. For this reason a training pot is used. The training
pot is larger than a bonsai container and holds the heavy roots, which
are gradually cut back, for a period of years until small, fibrous roots
develop.

All kinds of containers are used for training pots: clay saucers,
plastic containers, and wooden boxes of many different sizes. Many of
these clay and plastic pots are available at garden centers. The azalea
pot and the bulb pan are especially suitable. The pot should be just
large enough to accommodate the tree's root system. It should be similar
in shape to the bonsai pot which will eventually replace it.

For example, an upright tree, destined for a low, flat container, should
be grown in a fairly low training pot. A cascading tree, to be planted
later in a high bonsai pot, should be trained in an ordinary flower pot.

Make sure that all training pots you use have drain holes at least 1/2-
inch in diameter.

Choose a pot in which to display your bonsai when the training of your
bonsai is sufficiently advanced. The size and shape of this pot will
depend on the size and shape of the tree.

Trees trained in the cascade and semicascade styles look best in round
or rectangular pots. Plant the trunk in the center of the pot with the
branches sweeping down over the side.

Place upright trees slightly off-center (one-third the distance from one
end) in oval or rectangular pots. Place trees with thick trunks and
dense foliage in deep, heavy pots.

Branches of a bonsai should harmonize with the shape of a pot. If the
branches are longer on one side than the other, place the trunk off-
center in the pot. (See fig. 13.)

[Figure 13 (Photograph unavailable. Caption:)--The trunk of this bonsai
plant (Berchemia paucifolia) has cracks and scaly ridges that give it a
look of age. Note the off-center placement of the tree in the round
container.]

The color of the pot should contrast with the tree's foliage. Use white,
tan, or green pots for trees with brightly colored flowers or fruits.
Use unglazed pots with pines and deciduous trees.

Generally, bonsai containers come in five shapes: round, oval, square,
rectangular, and hexagonal. In each shape there is a wide variety of
sizes.

Bonsai containers can be obtained from some of the larger nurseries.
Chinese or Japanese hardware stores, and stores that specialize in
imported items, also offer containers.

Bonsai plants must be anchored to their containers until the roots take
hold. One method used to anchor the plant is to tie it down with wires
leading up through the screens that are placed over the drainage holes
in the container. After tying the plant to the container, adjust the
plant's elevation.

POTTING

At the end of the first year, the tree is usually transplanted from its
training pot (or from the ground) into a pot suitable to its dimensions.
Retain some of the original soil, and trim the roots if necessary. Cut
away any abundant growth of new roots at the base of the trunk before
repotting. If only a few roots have formed around the taproot, prune
these roots slightly. Prune the taproot again at the end of the second
year, and cut it short at the end if the third year. This final cutting
should be done when the new roots have appeared at the base.

REPOTTING

Repotting of bonsai plants is usually needed when soil insects damage
the plants, or when soil is in poor condition. Sometimes, however, a
soil condition can be corrected without repotting and disturbing the
roots of the plant. This is done by adding new soil around the outer
surface, or by removing plugs of soil and replacing them with a free-
draining soil mix.

The health of trees grown as bonsai depends largely on the care of
changing the soil in the pots and the proper pruning of surface roots.

A healthy bonsai puts out new surface roots every year. The growth of
these roots makes it difficult for vital water and air to penetrate the
soil. The surface roots will be nourished but the main root near the
trunk will die. Therefore, periodically cut back the main root and thin
out the surface roots.

A tree's rate of growth determines the frequency of repotting. Pines and
spruces, for example, need repotting only once every 3 to 5 years;
flowering and fruiting trees, every year or--depending on the variety--
every second year. Repot quick-growing species, such as willow and crape
myrtle, at least twice a year. These intervals apply to healthy trees
that have received proper care.

Repot your plants in the early spring when the first new buds appear. A
secondary season occurs in late summer or early autumn when, for a short
time, the roots check their growth. It is dangerous to repot in late
spring and early summer when the leaves are just open and still tender.

When the tree is in a dormant state it is unable to establish itself in
the new soil and root diseases are likely. For this reason, bonsai must
never be repotted in winter, except when kept in greenhouse culture.

[End of Growing Bonsai Part 3 of 4]

[Growing Bonsai Part 4 of 4]

GROWTH MEDIA

Soil mixtures vary a great deal depending on geographical area and
personal preferences. There are many conflicting ideas on the type of
mix to use.

Many growers find that bagged potting soil is satisfactory for potting
bonsai plants. If you use bagged soils, make sure they contain sphagnum
peat moss and coarse perlite in equal quantities. Bagged soils are
available in most garden supply houses.

Generally, mixing soil should have rapid drainage, a structure that
permits fine roots to develop, and contains decaying humus and mineral
nutrients. It should also be free of root rot and have a pH similar to
the tree's native soil. Try to avoid high levels of dry fertilizers in
the soil mix. Screen bagged soil to remove the fine clay particles.

A good basic mixture consists of one-third clay, one-third humus, and
one-third sand. If you live in an area where humus is not available,
then obtaining an artificial soil mix from your garden store or nursery
is the only answer. River or quarry sand can be purchased from lumber
yards and variety stores where it is sold under the name of white
aquarium sand.

SEASONAL CARE

Bonsai from miniature forest trees must live outdoors all the time. They
are brought into the house for short periods on special occasions.
Bonsai from forest trees will die if kept too long indoors, particularly
in overheated rooms. These bonsai may be brought inside once or twice a
week for 2 or 3 hours--during winter, spring, and autumn. They should
not be brought inside in summer unless the room is well ventilated.

Summer care

Bonsai are very sensitive and thrive best in localities that offer cool
nights, sunny days, and mist or rain almost daily. Most of the United
States does not have this climate, so special provisions must be made to
compensate for the lack of desired climatic conditions. Extremes in
light, rain, and wind are to be avoided.

Place your bonsai on a platform or table in your garden where the plants
can receive 3 to 5 hours of direct sunlight a day. The site should be
shaded, preferably in the afternoon. If the area is subject to drying
winds, put up screening around the plants to protect them. Screening
also serves to provide the plants with shade.

Water the entire bonsai--plant and soil--daily. If you skip even 1 day
you can permanently damage the plant. Make sure your plants are located
where rain can fall on them. However, plants should not remain wet or
water-logged for long periods.

Fertilizer

To maintain plant growth use fertilizer to supply nutrients. Maintain
the nutrient level in the soil mix throughout active growth with monthly
applications of a diluted liquid fertilizer. Apply fertilizer only
before and during active growth. For a liquid fertilizer you can use a
typical house-plant fertilizer (20-20-20 or its equivalent) diluted to
one-quarter strength on the label.

Fall care

During this period bonsai must be prepared to endure the approaching
cold. Plant growth must be slowed. Water plants less frequently to slow
growth, and, when growth slows, reduce applications of fertilizers.

Do not prune or cut any branches after mid-August. Do not use artificial
night-lighting (incandescent filament lamps) on plants after August 1.
To reduce winter dieback of flowering trees and maples make light
applications of 0-10-10 fertilizer.

Winter care

A major problem in winter is to protect bonsai against low temperatures
and drying winds. Bonsai can only be left outdoors in climates where
temperatures drop no lower than 28 F degrees. This is not the case
throughout most of the United States, so a greenhouse, pit, or coldframe
is necessary.

Winter frosts will seldom bother bonsai that are sheltered under the
foliage of a spreading tree. Watch out, however, during the frost period
for drying soil.

Coldframes

It is easy to construct a simple coldframe for bonsai. Before the ground
is frozen, dig a hole at least 1-1/2 feet in the soil. Make the hole as
long and as wide as you need for all your plants. Line the sides of this
hole with exterior grade plywood which extends 6 inches above the
surface. Put 4 to 6 inches of gravel in the bottom of the hole, set your
plant containers on this gravel, and spread straw around and over them.
Put a loose-fitting cover on the frame made of polyethylene sheeting or
any similar material.

Be sure the top of your coldframe is strong enough to withstand a heavy
load of snow. Ventilate on days when the air temperature is above 40 F
degrees to keep the plants cool and dormant.

To purchase a coldframe kit, check your local nurseries or see catalogs
of mail-order garden supply houses.

Spring care

Spring is the time when new bonsai are started. It is the time for any
pruning and training of last season's bonsai. The plants then have a
whole growing season to readjust to these changes.

Watering

In the summer, during hot weather when the temperature is over 90 F
degrees, water the bonsai plants one or more times a day. If the plants
are in an unusually sandy soil they will require watering three or more
times a day.

In early autumn, follow the watering directions for late spring. In late
autumn, follow the watering directions for early spring.

In winter, keep the trees in a coldframe and ventilate the plants on one
or more sides to keep them dormant. Check for dryness every 2 weeks.
Water the plants every second day, or less, as required. Keep in mind
that far more bonsai are killed by overwatering than by a lack of water.

PROPAGATING YOUR OWN BONSAI

Seedlings

Growing bonsai from seeds is a slow process, unless you intend to grow
plants whose maximum height will be 6 inches. A more nearly perfect tree
can be grown from seed because the trunk can be shaped from the
beginning to suit the grower.

To develop the trunk rapidly, plant seedlings in the ground outdoors;
seedlings are kept outside from 2 to 5 years, depending on the type of
material planted and its rate of growth.

Each spring, dig up the plant and prune its roots just as if it were in
a pot.

When you choose a seedling, select one that has small leaves to begin
with. For example, silk oak and cherimoya seedlings have been
successfully grown indoors.

Cuttings

Staring bonsai from cuttings is faster than starting them from seed.

Make cuttings in the late spring and early summer, just before the buds
open or after the new growth has hardened.

Plants that propagate easily from cuttings are olive, willow,
cotoneaster, firethorn, azaleas, and boxwood.

Layering

This is a simple and convenient method of rooting branches in the soil
while they are still attached to the parent plant. The branches
immediately have a well-established form and branch structure. Layering
often results in good, balanced root systems.

Mid-spring is the best time to do soil layering. Choose a branch that
has good form. Make sure the branch is low enough to reach the ground.
Mark a point about one foot from the end of the branch and dig a hole in
the ground 4 inches deep. In the soil, mix equal parts of sand and peat
moss made from ground bark.

Make a slanting cut on the underside of the branch. Insert a pebble in
this cut. Bend the branch back in the hole, taking care not to crack the
branch. Anchor the bent branch in a vertical position. Then cover it
with prepared soil, and water it.

In 9 months to a year the branch (layer) should have rooted. When this
occurs, it is ready for transfer to a bonsai pot. (Remember to cut the
stem just below the original cut when removing it for transfer.)

Softwood plants that are layered will root in 6 to 8 weeks. When they
have rooted, be sure to cut them form the parent plant and pot them.
Pinch off new buds until the layered stem develops a mature root system.
Remember to keep the layered area moist so that the root systems will
develop quickly.

Plants that propagate well by the layering method are: rhododendrons,
maples, pomegranate, cryptomeria, and many others.

Grafting

Grafting is complex and requires patience and practice, especially by
the novice bonsai grower. It is not as successful as the other methods
of propagation. One of the drawbacks for bonsai is that even after a
graft has taken, an ugly scar remains. The "side" or "notch" grafting
methods have the advantage of hiding the scar.

Grafting is usually done in the winter or early spring when the buds are
dormant. There are numerous methods of grafting, but the most popular
among bonsai enthusiasts are "cleft" and "whip" grafting.

DISPLAYING YOUR BONSAI

Indoor display

Before you bring your bonsai indoors to display them, water them first
and let them drain well. Wipe all dirt and dampness from the container.

Bonsai look well placed in front of a plain wall on a raised stand. The
Japanese display bonsai on a platform raised a few inches above the
floor in one corner of the living room. Paintings and scrolls are hung
against the wall at the back. Other objects, such as ceramic ware and
flower arrangements,are grouped with the bonsai on the platform.

If you set bonsai on a low stand or table, try using a small Japanese
folding screen behind it. These stands can be purchased in oriental
stores. It's a good idea to contrast the shape of the stand with the
bonsai container; the height of the stand should harmonize with the
height of the tree.

Bonsai in the garden

Display bonsai in the garden on simple shelves set on concrete blocks.
Place the shelves against an outside wall away from trees, and protect
them from the sun. Other good locations for bonsai are slat benches and
decks, either in the garden or adjoining the house. (See fig. 14.)
Bonsai in large containers look better displayed alone. Place them on
some kind of stand, rather than setting them on the ground.

[Figure 14 (Photograph unavailable. Caption:)--Bonsai tables for garden
display are high enough to prevent cascaded plants from touching the
ground. The lath overhead provides shade for the plants.]

End of GROWING BONSAI

United States Department of Agriculture

Home and Garden Bulletin No. 206

August 1973

[End of Growing Bonsai Part 4 of 4]

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