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The Yorkshire Bonsai guide
Bonsai Glossary
From akadama to yamadori: discover the words behind the trees. Plain-English explanations, familiar shapes and a little bonsai history.
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A living art, a shared vocabulary
You do not need to learn every Japanese term to enjoy bonsai. Start with the words you meet while choosing a tree or following its care guide. Japanese spellings and size classifications sometimes vary between books and clubs.
These are definitions, not a pruning calendar: care techniques should always match your tree’s species, condition and growing environment.
A
Air layering (toriki)
Encouraging roots to grow on a stem while it is still attached to its parent. Once established, the rooted section can become a separate tree.
Akadama
A granular Japanese clay-based growing medium used in many bonsai soil mixes. It holds moisture but gradually breaks down, so its condition matters when repotting.
Apex
The top or crown of the tree. Its position helps establish the tree’s overall direction and balance.
Apical dominance
The tendency for leading shoots to grow more strongly than shoots below them. Understanding it helps explain why selective pruning can balance a tree.
B
Back-budding
New buds developing further back on a branch or trunk. This can help rebuild a compact silhouette; the response varies between species.
Bonsai
The art of cultivating and shaping trees in containers to suggest the character of larger trees in nature. Bonsai describes a practice, not a species.
A little history. Japan developed its bonsai traditions from earlier Chinese practices of growing miniature trees and landscapes. The art continues to evolve worldwide.
Broom style (hokidachi)
An upright trunk dividing into a rounded crown of fine branches, reminiscent of a mature broadleaved tree.
C
Cascade (kengai)
A downward-flowing style whose main descending trunk extends below the pot’s base, recalling trees growing over steep edges.
Clip-and-grow
Developing shape through repeated cycles of extension and pruning. A chosen shoot becomes the next section of a branch or trunk.
D
Deciduous
A tree that sheds its leaves seasonally. A bare winter silhouette can reveal branching that summer foliage hides.
Defoliation
Deliberately removing some or all leaves as a refinement technique on suitable, vigorous trees. It is species-specific and unsuitable for weak trees.
Dormancy
A seasonal rest period when growth slows or pauses. Many temperate bonsai need this natural cycle, rather than year-round warmth indoors.
E
Evergreen
A tree that keeps foliage throughout the year. Individual older leaves or needles are still replaced; evergreen does not mean that nothing ever falls.
F
Forest planting (yose-ue)
Several separate trees arranged together to suggest a woodland, using differences in height and placement to create depth.
Formal upright (chokkan)
A straight, upright trunk that narrows towards the top, with the apex above the base.
G
Grafting (tsugiki)
Joining living plant parts so they unite and grow together. Bonsai growers may use it to introduce a branch or improve roots.
Guy wire
An anchored wire that pulls a branch into position. It works differently from wire coiled along the branch.
I
Informal upright (moyogi)
An upright composition with movement in the trunk, usually bringing the apex back above the base.
Internode
The section of stem between two nodes, where buds or leaves arise. Shorter internodes can help a small tree look proportionate.
J
Jin
An exposed dead branch or dead trunk tip, retained or shaped as a design feature.
In nature. Broken branches, drought and harsh weather can leave bleached deadwood. Jin echoes those signs of a tree’s life outdoors.
K
Kanuma
A light, acidic Japanese growing medium particularly associated with azaleas. It is a specialist option rather than a universal mix for every bonsai.
Kiryuzuna
A durable, granular bonsai substrate valued for drainage and air space around the roots. It is particularly associated with pines, junipers and other conifers, and can be used as part of a soil mix.
Kurodama
An inorganic growing medium sold in our range as natural volcanic pumice. It combines moisture retention with drainage and can be mixed with materials such as akadama or kanuma.
Kyodama
A coarse, porous grit used when potting and repotting bonsai. Its durable granules help retain moisture while allowing drainage, and it can be used alone or blended with other suitable substrates.
L
Literati (bunjingi)
A spare composition with a slender, expressive trunk and relatively little foliage. Empty space is an important part of its character.
Behind the name. The style is associated with the trees depicted in Chinese literati painting: suggestion and expressive line matter more than a full crown.
M
Mame
A term for very small bonsai. Size categories differ between organisations, so treat labels as guides rather than universal measurements.
N
Nebari
The visible spread of roots where the trunk meets the soil. A convincing root base gives the tree a sense of stability.
P
Penjing
The Chinese art of miniature trees and landscapes. Compositions may centre on trees, rocks, or combinations of land and water.
A little history. Penjing is a wider landscape tradition, not simply another name for a single bonsai tree. The National Bonsai & Penjing Museum even displays a stone composition called “Spring Rain”.
Pinching
Removing soft growing tips to manage extension and refine growth. The method and timing depend on the species and the grower’s aim.
Pumice
A porous volcanic material used in bonsai mixes. Its particles help balance moisture retention with air space around roots.
R
Ramification
The division of branches into progressively finer twigs. Good ramification gives a small tree a mature, detailed framework.
Repotting
Renewing the growing medium and managing the root system. It does not always mean moving into a larger pot.
Root pruning
Selective trimming of roots during suitable repotting work. The amount and timing depend on species, health and stage of development.
Root-over-rock (seki-joju)
A composition in which roots travel over a rock before reaching soil in the container below.
S
Sacrifice branch
A branch allowed to grow temporarily to help thicken a trunk or branch, then removed when it has served its purpose.
Semi-cascade (han-kengai)
A descending or outward-reaching style that stays above the base of the pot, unlike a full cascade.
Shari
An exposed strip or area of deadwood on the trunk. It contrasts with the living bark and can suggest age and weathering.
Shohin
A small bonsai category, commonly around 20cm or less in height. Exhibition conventions vary, and visual proportion matters as well as a ruler.
Display tradition. Shohin are often shown in coordinated groups, with different trees and stands forming a single composition.
Slanting style (shakan)
A tree whose trunk leans distinctly to one side, with roots and branches providing visual balance.
Structural pruning
Major pruning that establishes a tree’s framework. It involves different decisions from regular trimming and must suit the tree’s health and seasonal needs.
Substrate
The growing medium around the roots. A bonsai mix needs to hold useful moisture while allowing drainage and air exchange.
T
Taper
The gradual narrowing of a trunk or branch from its base towards its tip. It helps suggest scale and maturity.
U
Uro
A hollow in a trunk, natural or deliberately shaped. It can evoke an old branch wound rather than a projecting dead branch.
W
Windswept style (fukinagashi)
A composition suggesting persistent wind, with branches flowing predominantly in the same direction.
Wiring
Using carefully applied wire to guide the position of a trunk or branches. It must be monitored and removed before thickening growth causes damage.
Materials. Aluminium and copper are both used. Wire is a temporary training aid, not something intended to remain on the tree permanently.
Y
Yamadori
A tree collected from the wild for bonsai cultivation. Natural trunk character can be valuable; responsible collection requires permission and careful recovery.
Sources & further reading
Definitions written for Yorkshire Bonsai, with terminology and background checked against the following references.
- Bonsai terminology
- Bonsai styles
- Soils and substrates
- Pruning and growth
- Deadwood: jin, shari and uro
- Wiring
- Defoliation
- RHS: growing bonsai
- RHS: air layering
- Toronto Bonsai Society: lexicon
- New Zealand Bonsai Association: shohin
- National Bonsai Foundation: the evolving art of bonsai
- National Bonsai Foundation: stone penjing