Bonsai Plant Glossary
Bonsai Terms By Tom Regan
Having a working familiarity with bonsai
terminology will enable you to effectively express all facets of your bonsai
activities to others, both more and less skilled than yourself, in the
bonsai community. The following list of words and definitions will help you
on your way to becoming fluent in the unique language of bonsai:
Accent Plant - a small plant that is
put on view in conjunction with a bonsai; usually when a bonsai is being
formally displayed at a show or exhibition; also called a companion plant.
Air Layer - a method for propagating trees through the removal of a
large branch or section of trunk from an existing tree, or bonsai, to create
a new tree.
Akadama - a traditional Japanese bonsai soil that is comprised of the
red volcanic matter of Japan; used for thousands of years by bonsai artists
on most types of deciduous bonsai trees.
Apex - the very top or highest point of a bonsai tree.
Back budding - a process of encouraging new growth on a branch where
growth is currently non-existent.
Broadleaved - trees, mainly deciduous, with broad, flat leaves;
Bunjin - a traditional Japanese bonsai style; also called literati.
This is a tree that has a tall, slender trunk with foliage growing only near
the top; illustrating maturity and the casting off of material things.
Buttress - the area of a tree trunk where the roots meet the soil
surface; usually styled to convey strength.
Callus - the scar tissue that forms over a wound where a branch has
been pruned off of a tree; it is part of the tree's healing process.
Cambium - the thin layer of green colored cell tissue growing between
the bark and the wood of a living tree.
Canopy - all of the upper-most branches that form the top of a tree.
Chokkan - a traditional Japanese bonsai style; also called a formal
upright. This is a tree that has a very straight trunk with symmetrical
branching; illustrating strength and order.
Collected tree - finding and taking a tree from its natural habitat;
a tree that has been shaped by the forces of nature alone.
Conifer - a tree that bears cones; mainly evergreen trees such as:
pines, cedars, spruces and junipers.
Cross - a hybrid resulting from cross-fertilization between species
Crown - the upper section of a bonsai where the branches spread out
from the trunk.
Cultivars - cultivars are plants that have features desirable to the
person "cultivating" them. These desirable characteristics have
been deliberately selected and can be reliably reproduced in plants under
Cut-leaved - a bonsai that has leaves which are shaped in very
Deciduous - a tree that has a seasonal growth cycle where new foliage
is produced in the spring, then grows throughout the summer, turns colors in
autumn, and drops in the winter, leaving buds on the branches for next
spring's new foliage.
Defoliation - the practice of removing all leaves to encourage new
shoots and potentially smaller leaves.
Dieback - the death of the tips of branches, or whole branches, due
to extreme weather or possibly one of several diseases.
Divided leaf - a leaf formed of separate sections that emerge from a
Division - a method of propagating shrubs by carefully dividing the
root ball and replanting the separated sections.
Dormant - the period of the year when little or no growth occurs;
usually late autumn and throughout the winter months.
Dwarf - a variety or cultivar that is smaller than the species tree,
but retains all of the characteristics of a full size species tree.
Evergreen - a tree or shrub that retains its leaves throughout the
Fertilizer - is "food" for trees, shrubs and plants;
usually comprised of NPK: Nitrogen for the foliage, Phosphorous for the
roots, and Potassium for the flowers.
Foliage pad - a mass of foliage on a branch; sometimes referred to as
Fruit - the part of a plant that carries the seeds; usually berries
or fleshy or pod like.
Fukinagashi - a traditional Japanese bonsai style; also called
windswept. This is a tree that has its trunk and branches swept back in one
direction; illustrating a tree exposed to very forceful winds.
Genus - a unit of classification for a group of closely related
Germination - the moment a seed starts into growth, developing roots
Girth - the circumference of the trunk of a tree, measured at just
above the root base.
Grafting - is a commonly used method for propagating trees, when
propagation by seeds or cuttings is impractical or impossible.
Han-Kengai - a traditional Japanese bonsai style; also called
semi-cascade. Where the branches and trunk of a tree are swept down to one
side, but not below the top lip of the container; illustrating a tree
subject to violent winds and weather.
Hardy - a term used to describe trees capable a withstanding winter
Hokidachi - a traditional Japanese bonsai style; also called broom.
Where the trunk is straight with symmetrical branches and has its foliage
arranged in a semi-circular dome or broom shape.
Humidity - the amount or degree of moisture in the air.
Internodal distance - the length of stem between two nodes or leaf
Ikadabuki - a traditional Japanese bonsai style; also called raft.
Where the tree is laid on its side and its branches are trained vertically
and arranged in a group formation.
Ishitsuki - a traditional Japanese bonsai style; also called root
over rock. Where the tree has its roots arranged so they have grown over and
in the crevices of a rock.
Jin - is a branch, which has been stripped of its bark and cambium to
represent a dead branch; illustrating great age or harsh conditions.
Juvenile foliage - the young leaves of a tree that produces two
distinct shapes of leaves; the second type being mature foliage.
Kabudachi - a traditional Japanese bonsai style; also called clump.
Where the trees' trunks all grow from the same point on the root mass and
are more crowded in appearance than a regular group planting.
Kengai - a traditional Japanese bonsai style; also called cascade.
Where the branches and trunk of the tree are swept to one side and hang
below the container; illustrating a tree on the edge of a mountain cliff
subjected to fierce winds.
Leader - the main shoot at the top of a tree, usually indicating the
uppermost continuation of the trunk.
Lime Sulphur - a chemical used to whiten or bleach a section of
stripped branch or trunk in order to preserve a jin or shari.
Loam - a soil mixture comprised of clay, sand and organic matter.
Mame - a term used in size classification of bonsai trees; this being
a small bonsai.
Moyogi - a traditional Japanese bonsai style; also called informal
upright. Where the trunk curves through its taper up to the apex.
Nebari - the exposed surface roots of a bonsai.
Needle - a type of leaf that is narrow and usually of a stiff
texture, like those found on a black pine tree.
New wood - a stem or twig on a bonsai that originated during the
current season's growth.
Nitrogen - an essential element of plant nutrition; identified by the
chemical symbol N; aids in growth of stems and leaves.
Node - the point on a trunk or branch where the leaf buds emerge.
Old wood - a stem or twig on a bonsai that originated during the
previous season's growth or at an earlier time.
Peat - partly decomposed organic matter; when it is used as an
ingredient of potting soil it assists in moisture retention.
Perlite - a form of volcanic rock that is heat treated to develop a
lightweight, coarse granule that when used as a component of potting soil
has advantageous ventilation and water retention properties.
Phosphorous - another essential element of plant nutrition;
identified by the chemical symbol P; aids in development of roots, ripening
of fruits and seeds.
Pinching - is a technique used in bonsai cultivation of controlling
and shaping the growth of foliage by pulling off soft new shoots with the
finger and thumb in a pinching motion.
Potassium - the third essential element of plant nutrition;
identified by the chemical symbol K; it encourages strong new growth,
development of flower buds and fruit formation.
Pot-bound - the adverse state of a container grown plant where the
root growth has filled the container to the extent of eliminating all vital
Prostrate - the characteristic growth habit of a plant that naturally
tends to grow along the ground instead of upright.
Pruning - the process of controlling the shape and growth rate of a
tree by cutting back the shoots, stems and branches.
Raceme - a type of elongated flower that is composed of individual
stalks all growing from a central stem; ex. Flower type found on wisteria
Ramification - the dense branching structure of a bonsai that only
develops after years of repeated pruning of the branches.
Repotting - the practice of replanting a bonsai tree at regular
intervals to perform health maintaining tasks such as: root washing,
inspecting, pruning, soil refreshing, and potting in a different or larger
pot; all imperative to the health of a bonsai.
Rootball - the large mass of roots and soil visible when a tree is
taken out of its pot or pulled from the ground.
Root pruning - the practice of cutting back the roots of bonsai in
order to make room in the container for fresh soil and to encourage new root
Rootstock - is the root system and main stem to be used as the base
of a new tree when propagating through grafting.
Scion - is a small section of a tree, which contains all of the
desirable characteristics of the parent tree that will be propagated into a
new tree through grafting on top of the rootstock.
Shakan - a traditional Japanese bonsai style; also called slanting.
Where the trees' trunk, appears similar to the formal upright style, but the
trunk is slanting to one side.
Shari - an area where the bark and cambium have been removed from the
trunk to suggest the struggle against fierce weather such as: wind,
lightning, snow and ice.
Species - the unit of classification for a plant with identifiable
Suiseki - stones that appear to look like large boulders or mountains
and represent the spirit or essence of each; sometime used in a formal
Taproot - the large root of a tree that grows vertically downward,
anchoring it into the ground; it is usually referred to in bonsai, because
of its need to be pruned shorter or removed for container cultivation.
Tokonoma - a Japanese tradition of creating a specific area in the
home where bonsai, accessory plants, Suiseki, and scrolls are displayed
together in harmony.
Wound sealant - a number of compounds formulated to seal cuts made on
branches or the trunk of bonsai to prevent the loss of moisture and promote
Yamadori - trees collected from the wild, which have been shaped by
nature alone and have been collected to be developed into bonsai.
Yose-ue - a traditional Japanese bonsai style; also called a group or
forest. Where the trees are arranged in a container to resemble a group or
forest of trees.
Content used by permission from Bonsai