Bonsai glossary

Bonsai terms explained, from nebari to yamadori.

Air layering (ground layering): A propagation technique where a branch or trunk section is wounded and wrapped in moist medium to force roots to grow at that point, so the rooted portion can later be separated as a new tree. Often used to create instant nebari or salvage a section with good movement.
Akadama: A granular, baked clay soil from Japan prized as a bonsai substrate for its water retention, drainage, and ability to encourage fine roots. It breaks down over time, which signals when repotting is due.
Apex (crown): The topmost point or growing tip of a bonsai, which typically defines the tree's direction and finishes its silhouette. In most styles the apex is positioned over or near the base for visual balance.
Back-budding: The growth of new buds on older, interior wood behind the branch tips, usually triggered by pruning, pinching, or defoliation. It is essential for developing compact, well-ramified branches and keeping foliage close to the trunk.
Bar branch: Two branches emerging from the same point on opposite sides of the trunk at the same height. It is considered a fault because it creates visual tension and can cause swelling, so one branch is usually removed or repositioned.
Broom (hokidachi): A style with a straight upright trunk that divides into many fine branches forming a rounded, fan-shaped crown, resembling an upturned broom. It suits deciduous species with fine ramification such as zelkova and elm.
Candle: The elongated new shoot of a pine before its needles open, named for its candle-like shape. Candles are pinched or cut to control vigor, needle length, and branch density.
Cascade (kengai): A style in which the trunk grows downward below the base of the pot, evoking a tree clinging to a cliff or growing over water. It is planted in a tall pot to accommodate the descending line.
Chop (trunk chop): Cutting the trunk down to a much lower height to force new growth and build taper or a new leader from that point. A common early step in developing thick, field-grown or collected material.
Chopstick: A simple wooden or bamboo stick used to work fresh soil into the root mass during repotting, eliminating air pockets. Also handy for checking soil moisture and testing root stability.
Colander (pond basket): A perforated plastic container used as a growing pot to give roots maximum air exposure, encouraging vigorous, fibrous root development. Popular for accelerating trunk thickening and nebari during the development phase.
Concave cutter: A specialized bonsai plier whose curved blades cut a hollow, dish-shaped wound when removing a branch. The concave cut heals flatter and with less scarring than a flush cut.
Cut paste (wound sealant): A putty or paste applied over pruning wounds to reduce moisture loss, protect against dieback, and speed callus formation. Available in colored and clear forms for different species and situations.
Cutting: A severed piece of stem, root, or shoot rooted to produce a genetically identical new plant. Cuttings are an inexpensive way to propagate bonsai stock and preserve desirable traits.
Decandling (candle cutting): Removing the spring candles of vigorous pines, usually black and red pine, to force a second flush of shorter needles and more numerous buds. Timing and strength of the tree determine how much to remove.
Deadwood: The bleached, weathered wood features on a bonsai that suggest age and hardship in nature, chiefly jin and shari. Deadwood is often carved and treated to preserve it and enhance character.
Defoliation (leaf cutting): Removing all or a portion of a deciduous tree's leaves in the growing season to reduce leaf size, promote back-budding, and increase ramification. It stresses the tree, so it is done only on healthy specimens.
Fertiliser cake (fertilizer cake): A solid, slow-release cake or pellet of organic fertilizer placed on the soil surface to feed the tree gradually with each watering. Often held in place with a small mesh basket to deter pests and displacement.
Forest planting (yose-ue, group planting): A composition of several trees planted together in one container to depict a grove or woodland. Trees are usually of the same species and arranged in odd numbers with varied heights for natural depth.
Formal upright (chokkan): A classic style with a perfectly straight, vertical trunk that tapers evenly from base to apex, with branches arranged in balanced tiers. It represents a tree grown in open, ideal conditions.
Guy wire: A length of wire anchored to the pot or another branch and used to pull a branch or trunk into position through tension rather than by coiling. Useful for bending thick or brittle branches that ordinary wiring cannot hold.
Informal upright (moyogi): The most common bonsai style, featuring an upright trunk with gentle curves and movement while the apex remains over the base. It looks natural and forgiving, making it popular for beginners.
Internode: The length of stem between two nodes or leaf-bearing points. Short internodes are desirable in bonsai because they allow compact, densely ramified branch structure.
Inverse taper (reverse taper): A flaw in which the trunk or a branch becomes wider higher up rather than tapering toward the top. It disrupts the illusion of age and is usually corrected by removing the cause, such as bar branches or wire scars.
Jin: A deadwood feature created by stripping the bark from a branch or the top of the trunk to leave a bleached, weathered spar, suggesting a limb broken by lightning or storms. Often treated with lime sulfur for preservation and color.
Jin pliers: Heavy pliers with a broad, flat jaw used to crush, strip, and peel bark when creating jin and other deadwood. The wide grip helps split fibers cleanly for a natural appearance.
Kabudachi (multi-trunk, clump): A style in which several trunks rise from a single root base, forming one unified tree. Trunks are usually an odd number and vary in thickness and height for a natural clump effect.
Kanuma: A soft, acidic, yellowish volcanic pumice soil from Japan used mainly for acid-loving plants, especially azaleas. Its high water retention and low pH suit ericaceous species.
Leader: The dominant shoot or branch chosen to extend the trunk line or a branch, typically the future apex during development. Selecting and replacing leaders builds taper and movement over time.
Lime sulfur (lime sulphur): A liquid solution painted onto jin and shari to bleach the wood white, preserve it against rot, and enhance the aged look. It can be tinted darker for a more natural weathered tone.
Literati (bunjin, bunjingi): An elegant, minimalist style with a slender, often twisting trunk and sparse foliage confined near the top. Inspired by East Asian ink paintings, it conveys age, struggle, and refinement.
Mame: A miniature bonsai roughly under about 10 centimeters tall, small enough to sit in the palm of a hand. Its tiny scale demands frequent watering and delicate refinement.
Movement: The direction, curves, and flow of a trunk or branch that give a bonsai visual dynamism and a sense of a life shaped by nature. Good movement guides the viewer's eye and supports the illusion of age.
Muck (keto, keto-tsuchi): A sticky, clay-like mix, often peat-based, used to build up planting mounds, hold soil on rock plantings, and seal slab edges. It keeps roots and substrate in place where a normal pot wall is absent.
Nebari (root flare): The surface roots that spread visibly from the base of the trunk. A wide, radial, well-balanced nebari anchors the composition and is one of the strongest indicators of a mature, high-quality bonsai.
Pad (foliage pad): A defined cloud or layer of foliage on a branch, separated from other pads by open space. Well-developed pads give a bonsai clear structure and the impression of age.
Pinching: Removing soft new growth with the fingers to control extension, encourage back-budding, and maintain the silhouette. Common on junipers and elms during active growth, though some conifers respond poorly to it.
Primary branch: A main branch growing directly from the trunk, from which secondary and finer branches subdivide. Primary branches establish the fundamental structure and placement of a tree's design.
Pumice: A lightweight, porous volcanic rock used as a bonsai substrate component to improve drainage and aeration while holding some moisture. It is stable and does not break down like akadama, so it is often mixed with other components.
Raft (ikadabuki): A style created by laying a trunk on its side so its branches turn upward and grow as individual trunks, sharing one root system. It mimics a fallen tree that survived and re-rooted along its length.
Ramification: The progressive division of branches into ever finer twigs, building density and a delicate, mature canopy. It is developed over years through repeated pruning, pinching, and defoliation.
Repotting: Periodically removing a bonsai from its pot to prune the roots and replace some or all of the soil, keeping the tree healthy and vigorous. Usually done in early spring before the growing season, at intervals that depend on species and age.
Root over rock (sekijoju): A style in which roots grip and drape over a rock as they descend into the soil below, evoking a tree established on rocky terrain. The exposed roots are trained against the stone over several years.
Sacrifice branch: A branch left to grow unchecked to thicken the trunk or heal a wound, then removed once it has served its purpose. It speeds development while the final design branches remain restrained.
Secondary branch: A branch that grows from a primary branch and in turn gives rise to finer tertiary twigs. Secondary branches fill in the structure and support the development of foliage pads.
Semi-cascade (han-kengai): A style in which the trunk grows outward and downward but not below the base of the pot, resting roughly at or slightly below the rim. It suggests a tree on a slope or overhanging a bank.
Shari: A strip of deadwood along the trunk where the bark has been removed to expose bleached wood, imitating natural scarring from age, weather, or injury. It is carved and preserved to contrast with the living vein of bark.
Shohin: A small bonsai generally up to about 20 centimeters tall, larger than mame but still portable in one hand. Shohin are prized for packing mature character into a compact form.
Taper: The gradual narrowing of a trunk or branch from base to tip, a key cue that makes a tree read as old and stable. Building taper often requires trunk chops, sacrifice branches, and careful leader selection.
Uro (hollow): A hollow or cavity in the trunk, typically where a large branch was removed or wood decayed, suggesting an old wound. Unlike shari, an uro is a recessed hole rather than a flat exposed face.
Whip: A young, unbranched seedling or single slender shoot at an early stage of development. Whips are cheap starting material that can be trained from scratch for trunk movement and taper.
Windswept (fukinagashi): A style in which the trunk and all branches sweep to one side as though shaped by constant prevailing wind. It conveys exposure and endurance in a harsh environment.
Wire bite (wire scar): Scarring left when training wire is not removed in time and the branch grows over it, cutting into the bark. Scars can be slow to heal, so wire must be watched and removed before it bites.
Wiring: Coiling aluminum or copper wire around a trunk or branch to bend and hold it in a chosen position while it sets. It is the primary means of shaping bonsai and must be removed before it scars the bark.
Yamadori (collected tree): A tree collected from the wild, often carrying the gnarled trunks, deadwood, and compact growth of decades in a harsh habitat. Prized for natural character, yamadori require careful collection and recovery before styling.