There's a lot of information about bonsai gardening, but most of it is aimed at individuals who already have a grasp on basic bonsai terminology and techniques. Even bonsai books, which are intended for beginners, assume that you have a basic knowledge of tree and plant terminology. If you need a little help, check out our Bonsai Glossary. While it doesn't cover all the Japanese terms used in bonsai gardening; it is a helpful tool for every level of bonsai enthusiast.

The Bonsai Glossary attempts to define all the terms in "plain English." However, some of the definitions can be cryptic because they rely on other terms that may not be familiar to you.


Accent Plant : Is a small plant displayed next to a bonsai. Accent plants are typically used when a bonsai is being formally displayed at a show or exhibition. Accent Plants can include any perennial, bamboo or grass.

Air Layering: Is a method of propagating bonsai. Layering is more complicated than taking cuttings, but has the advantage that the propagated portion can continue to receive water and nutrients from the parent plant while it is forming roots. This is important for plants that form roots slowly, or for propagating large pieces. 

Akadama: Classic Japanese Bonsai soil meaning red clay balls. Imported for Japan , this volcanic soil has been used for thousands of years by bonsai artists on most types of deciduous bonsai trees.

Apex: The highest point of the tree. On a bonsai, this can be a single branch or a series of small branches . It can also be foliage or jin.


Back budding: Process of encouraging new growth on a branch where growth is currently non-existent. Back budding occurs when new buds appear on "old" wood.

Bleeding: The loss of sap caused by wounding or pruning.

Bonsai:  Japanese term for the art of cultivating and training a plant to create the illusion of a dwarfed tree. Bonsai is a Japanese word made up of two characters or word phrases, "bon" and "sai". Bon is pronounced as the English word "bone", and means pot, container or tray. Sai is pronounced as the English word "sigh" and means tree or plant in Japanese.

Branch bender: A clamp or jack used to bend branches or trunk into a different position .

Branch splitter: Also known as a trunk splitter, this cutting tool is specially designed to split trunks with minimal residual damage.

Buttress: Also known as root-flare, it's the area of a tree trunk where the roots meet the soil surface; usually styled to convey strength.


Chlorosis: A yellowing of leaf tissue due to a lack of chlorophyll. Possible causes of chlorosis include poor drainage, damaged roots, compacted roots, high alkalinity, and nutrient deficiencies in the plant.

Callus : Woody 'scar' tissue that forms over a wound where a branch has been pruned. It's the trees healing process.

Cambium: The layer of living tissue [typically green] between the sapwood and the bark. In regions where there are alternating seasons, each year's growth laid down by the cambium is discernible because of the contrast between the large wood elements produced in the spring and the smaller ones produced in the summer. These are the annual rings, by which the age of a tree can be established.

Concave cutters: a bonsai tool used to remove branches with a flush or slightly depression cut. C oncave cutters are one of the most important bonsai tools you can own. Also known as Mataeda Hasanmi, they are necessary to style bonsai and pre-bonsai nursery stock. There are specifically designed to cut branches flush to the trunk. This type of cut allows the wound to heal quickly and smoothly, and without creating an unsightly bump on the trunk of your bonsai tree.

Canopy: The peripheral foliage of the upper branches and those on the outer part of the tree.

Crown: Upper part of a tree where branches spread out from the trunk and define your bonsai silhouette.

Conifer: A tree that bears cones; mainly evergreen trees such as: pines, cedars, spruces and junipers. Coniferous trees have small and waxy leaves, sometimes needles, which are usually kept all year.

Cut Paste: Wound sealant specially made to promote the healing and keep sap from bleeding. Very popular with experienced bonsaiists.


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. Deciduous trees enter a state of dormancy annually. 

Dieback: Death of shoots or branch tips caused by drought, insects, disease, lack of light or extreme weather conditions.

Defoliation: Leaf pruning, whereby some or all of the leaves are removed to encourage new shoots and smaller leaves which can greatly increase ramification.

Dormancy - Is the resting period for bonsai, where little or no growth is produced - usually autumn and 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. Dwarfs are typically compact and slow growing.


Evergreen : "Evergreen" refers to trees that normally retain most of their foliage (needles) through the winter. Pine and juniper are examples.


Feeder root: Fine roots that absorb water and nutrients from the soil.

Feng Shui: Translates literally to "wind-water". Feng Shui is the ancient Chinese art of placement. The goal of Feng Shui is to achieve harmony, comfort, and balance, first in ones environment and then in one's life.

Fertilizer: This is "food" for your bonsai, shrubs, and plants usually comprised of NPK: Phosphorous for the roots, Nitrogen for the foliage, and Potassium for the flowers.

Foliage pad: Cloud-shaped foliage mass on a branch . Foliage pads are shaped by training the individual branches with bonsai shears and bonsai wire.

Forest Bonsai: Created from several small plants of the same variety to simulate a forest in nature. 

Fungicide: A chemical compound used to prevent the growth and spread of fungus , which can cause serious damage to a bonsai.


Germination: Is the process by which a bonsai seeds leaves the dormant state starts into growth, developing roots and shoots.

Grafting: Is a method of propagating bonsai where the tissue of one tree is encouraged to fuse with that of another tree. The stem of one plant is fused with another so they grow together with the benefit of adding foliage where none previously existed on a bonsai.

Girth: The circumference of a Bonsai tree measured at its widest point or at just above the root base. 


Hair Roots: Fine roots that absorb water and nutrients from the soil. 

Hard pruning: Involves cutting all stems to only a few inches above the ground. This is done to renovate an overgrown shrub. Not all shrubs respond well to this treatment - it should be used only on vigorous growing shrubs.

Hardiness: The plant's ability to survive in the extreme temperatures of a particular geographic region. Plants can be cold hardy, heat tolerant, or both. Hardy is a term used to describe trees capable a withstanding winter frost. U.S. Department of Agriculture's tree and plant hardiness zone map is one good guide in helping you determine a plant's ability to withstand an average minimum temperature. 

Humidity : The amount or degree of moisture in the air.


Ikebana: Ikebana (Japanese: literally "living flowers") is the Japanese art of flower arrangement. The arrangements follow strict rules for representing heaven, earth, and people.

Insecticide: A chemical (synthetic or organic) used to kill or repel insects. There are numerous botanical and mineral powders that are toxic to insects, as well as biodegradable chemicals such as insecticidal soaps.

Internodes: On a stem, there are nodes where the leaves, buds, and other stems originate. Between the nodes is a length of stem called the internodes.


Jin : Pronounced JEEN is a Japanese term that refers to the deadwood on the ends of branches or trunk . Jin can be either an old branch or a protruding part of the trunk. Jins are artificially created from unwanted branches by stripping the bark and cambium to represent a dead wood.


Kiyonaal: A quick drying sealant and grafting aid contains insecticides and fungicides and forms a smooth, dark green cover that remains quite flexible. As the callus forms, the paste drops off gradually without leaving marks.


Lava : A bonsai soil amendment formed from crushed volcanic ash.

Layering: A method of propagation in which a stem is induced to send out roots by surrounding it with soil.

Leader: The main shoot at the top of the tree.

Lime sulphur: Chemical used to used to preserve your Jin and Shari (dead wood) on your bonsai. It whiten the stripped branch or trunk in order to mature a jin or shari. It also acts like the cut paste in stopping intrusion of infection to the tree and will bleach the wood giving it a natural color. 

Loam: A rich soil composed of clay, sand, and organic matter.


Mame: Mame (pronounced "Ma-May") refers to the size of a bonsai. Mame bonsai should ideally be no more than 10cm in height and can be held in the palm of a hand. 

Mesophyll: The spongy inner tissue of a leaf, functionally similar to the cortex of stems and roots, where the raw materials - carbon dioxide and water vapor are held during the process of photosynthesis.

Mycorrhiza: I s a white beneficial fungus that is often found in the soil around pine trees. It usually appears to be small mats of white filaments each about 1/4 inch long , helping them absorb nutrients.


N.P.K. : Acronym for the three major bonsai nutrients and used to describe the amounts of each readily available.' N' is for nitrogen,' P' for phosphorus, and' K' for potassium.

Nebari: The Japanese term for the exposed surface roots. It's the spread of roots from which the lower trunk originates out of the bonsai soil.

Needle: A very narrow leaf, often evergreen and usually of a stiff texture, like those found on a pine tree.

Nitrogen: An essential element of bonsai nutrition and identified by the chemical symbol N; Nitrogen help to develop foliage and stem growth.

Node: The area of a bonsai [trunk or branch] where leaf buds emerge. 


Petiole : In a simple leaf, the petiole is the structure that attaches the leaf blade to the stem.

Perlite : Volcanic ash that has been exposed to very high heat expands to form perlite. It is very light weight and is often used in potting mixes to encourage good drainage, as well as to keep the soil from compacting. Because it is also porous, it helps to maintain soil moisture. Its size ranges, but it is about as large as gravel. 

Phloem : A layer of tree tissue just inside the bark that conducts food from the leaves to the stem and roots. See Cambium.

Phosphorous: An essential element of bonsai nutrition and identified by the chemical symbol P. It encourages root development and also ripening of fruit and seeds.

Photosynthesis: The process by which plants convert water and carbon dioxide into carbohydrates, using sunlight as the source of energy and the aid of chlorophyll.

pH: Measure of soil acidity. The pH is a measure of the acidity or basicity (alkalinity) of a material when dissolved in water. It is expressed on a scale from 0 to 14. Roughly, pH can be divided into the following ranges:

pH 0 - 2 Strongly acidic
pH 3 - 5 Weakly acidic
pH 6 - 8 Neutral
pH 9 - 11 Weakly basic
pH 12 - 14 Strongly basic 

Pinching:  A technique used to control and shape soft new growth of foliage, by carefully pinching or pulling off small shoots with the finger and thumb in a pinching motion.

Pot: A growing container for bonsai, usually high-fired clay. The Chinese or Japanese word bon means "tray" or "shallow pot". To fully appreciate the beauty of a bonsai, the pot you chose should compliment your tree. 

Potassium: The third essential element of plant nutrition and identified by the chemical symbol K. It encourages strong new growth, development of flower buds and fruit formation.

Pot-bound : Refers to the state of a container grown plant where the root growth has filled the container to the extent of eliminating all vital air spaces. When a plant gets too large for its pot, the roots circle around inside the pot and start to restrict themselves. If your plants seem to dry out more quickly than they used to, but are otherwise healthy, they are probably pot bound. There are simply too many roots in the pot and not enough soil is left to hold and distribute water.

Pruning : The process of controlling the shape and growth rate of a bonsai by cutting back the shoots, stems and branches.

Pumice : It's a light-colored volcanic rock containing abundant trapped gas bubbles formed by the explosive eruption of magma. It's often used as a bonsai soil amendment. 


Raffia : Originates from the raffia palm. The fiber, which is soft, pliable, strong, and nonshrinking when wet, is torn in thin strips from these leaves. After being dried in the sun, raffia takes on a yellowish-tan hue, but can be dyed in other colors. It's used to wrap branches and trunk before bending. It will help reduce the likelihood of splitting branches.

Repotting : The practice of taking a pot-grown bonsai out of its container to refresh the soil and encourage renewed root growth. It's also a great time to select a new or larger pot and its imperative to the health of a bonsai.

Rootball : The large mass of roots and soil visible on a bonsai when removed from its pot.

Root pruning : The practice of cutting back the roots when repotting from one pot to another will encourage new root growth and promote future growth.

Rooting hormone: A powder or liquid growth hormone is used to promote the development of roots on a cutting. It's formulated for the propagation of cuttings and stimulate the development of adventitious roots .


Sphagnum moss: Type of moss used for the lining of hanging baskets and as a soil amendment, or as a rooting medium in the propagation of trees by air layering.

Shari : Japanese term for exposed deadwood on the trunk of a bonsai (as opposed to Jin which is a deadwood branch or protrusion). It's the area where the bark and cambium have been removed from the trunk to suggest struggles against natural weather conditions such as wind, lightning, snow, and ice.

Shohin: Bonsai that are less than 10 inches tall.

Soil Sieve: Used to grade soils for layering and to remove fine dust that inhibits proper drainage.

Stratify: Natural process whereby seeds are exposed to low temperatures in order to get seeds to germinate. These conditions can also be recreated artificially using a refrigerator or freezer.

Suiban: A Japanese ceramic tray without drainage holes to display viewing stones (see suiseki), or for rock plantings, which are usually stood in water. 

Suiseki: 'Viewing stones' that suggest a mountain scene or landscape, usually displayed in shallow pots or specially carved wooden stands. Suiseki (Sui = water, Seki = stone) is the study and enjoyment of naturally formed stones as objects of beauty. The art of Suiseki involves the collection, preparation and appreciation of unaltered naturally formed stones. These stones are found in mountain streams, on windblown deserts, along ocean beaches - anywhere that nature may have deposited or shaped them. 


Tokonoma: A tokonoma is a small raised alcove where individual specimen bonsai are displayed, consisting of three elements, the bonsai tree (man), a scroll (heaven) and an accessory (earth). Tokonoma is a traditional display area in a Japanese house where bonsai are brought inside for a short period and displayed with accent plantings and calligraphy.

Transpiration: The natural process of water loss from the surfaces of leaves and plant stems. 

Tufa rock : P ronounced "toofa is a type of soft limestone rock, easily carved and ideal for rock plantings. Tufa is formed when water evaporates from lime-rich waters, leaving calcite (calcium carbonate) to crystallize, often with impurities of iron oxides (rust), which give tufa its yellow and red coloration.

Tachiagari : Movement of the trunk that goes from the rootbase (nebari) up to the first branch.


Variegated leaf: A green leaf design which is blotched, edged or spotted with yellow, white or cream color.

Vermiculite: This is a mineral called mica that is heated and puffed up to form lightweight, sponge-like granules capable of holding both water and air. Useful in rooting seedlings .


Wound sealant: A compounds formulated to seal cuts made on branches or the trunk of bonsai to prevent the loss of moisture and promote heeling.

Whitefly: A small flying sap sucker that is of the aphid family and settles on indoor plants, sometimes in large numbers. The health of the plant can be severely compromised if not treated with an appropriate spray.


Yamadori: Japanese term for a tree collected from the wild mountain, or a tree dwarfed "in the wild" by natural circumstances.


Zen: From the Japanese word meaning "meditation". It is the form of Buddhism which developed in Japan .

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