Glossary of Bonsai Terms
Accent plant: A separate, often seasonal, planting of grasses, bulbs, or small herbaceous plants displayed with a formal bonsai.
Accessory plant: Another term for an accent plant; also, an extra plant used as underplanting for a bonsai group planting.
Adult foliage: The mature leaves of a tree with a distinctly different type of young foliage.
Air layering: Propagation method that encourages roots to form on a tree trunk or branch.
Apex: In bonsai, this usually means the top part of the tree.
Aspect: A position facing a certain direction, especially in relation to the direction of the prevailing winds and sunlight.
Broad-leaved: Describing a plant that has broad, flat leaves.
Broom style: With an even, domed head of twiggy branches.
Bud break: When a leaf bud opens enough to show a green tip.
Bud burst: Moment when newly opened leaves begin to unfurl.
Callus: Corky-textured tissue that forms over a wound on a branch.
Cambium: Thin cell layer between bark and wood of woody plants.
Cascade style: With a trunk that leans to finish below the pot rim.
Clasped-to-rock style: With roots planted on a rock, not in a pot.
Clump style: With several trunks growing up from the same root.
Collected tree: A naturally dwarfed tree taken from the wild.
Compound leaf: A leaf comprising two or more separate but similar parts, called leaflets.
Conifer: A tree, often evergreen, that bears cones containing seeds.
Cross: A hybrid plant produced by deliberately cross-fertilizing species or varieties.
Crown: The upper part of the tree where the branches spread out from the trunk.
Cultivar: Variant plant produced in cultivation; indicated by single quotation marks in its botanical name (e.g. Picea abies ‘Little Gem').
Cut-leaved: Describing a tree or a shrub with segmented leaves.
Deciduous: Describing a tree or shrub that loses its leaves annually and often remains bare of leaves all winter.
Die-back: The death of young shoots, due to cold or disease.
Divided leaf: A leaf that is composed of separate sections on a common base.
Division: Propagation of shrubby plants by dividing the rootball and replanting the sections.
Dwarf: A variety, form, or cultivar smaller than the species plant, but otherwise similar.
Ericaceous: Describing plants in the family Ericaceae; generally, indicating lime-hating plants.
Evergreen: Describing a tree or shrub that keeps its leaves all year.
Formal upright style: With a straight, vertical trunk.
Fruit: The seed-bearing part of a plant; which may be a fleshy berry, nut or pod-like seed case.
Genus: The unit of classification for a group of closely related plants; shown by the first word in the botanical name (e.g. Picea).
Germination: The moment when a seed starts into growth.
Group-planting style: With three or more trees planted to look like a copse or woodland.
Habit: The characteristic growth pattern of a plant.
Hardy: Describing plants that are able to withstand winter frost.
Hermaphrodite: A self-fertilizing plant with both male and female reproductive organs.
Informal upright style: With a curving, upright trunk.
Internodal distance: The length of stem between two nodes (leaf joints).
Juvenile foliage: Young leaves of a tree that has distinctly different adult foliage.
Leader: Generally, the main shoot, at the tip of a branch, that extends the branch growth; in bonsai, usually the uppermost continuation of the trunk.
Lifting: Removing a plant from the ground with its rootball (roots and surrounding soil) intact.
Literati style: With a gracefully twisting or curving trunk.
Loam: A loose soil composed of a balanced mixture of clay, sand, and decomposed organic matter.
Mist-spraying: Using a sprayer to provide humidity, in a spray of very fine water particles.
Needle: A leaf that is narrow and relatively hard in texture.
New wood: Twig, branch, or stem of current season's growth.
Nitrogen (N): Essential element of plant nutrition; for growth above the ground, especially green I issue in leaves and stems.
Node: The points on a twig or branch where leaf buds and twigs appear; also, may be the source of a new shoot.
Nursery bed: The ground used for growing either seedlings or young plants.
Old wood: A twig, branch, or stem of previous growing season, or earlier.
Panicle: A group of flowerstalks, each bearing many small flowers.
Pinnate: Describing a compound leaf with leaflets on both sides of the main leaf axis.
Peat: Partly decomposed organic matter, found in bogs or heaths; it helps retain water in potting soil.
Perlite: Lightweight, coarse granules of volcanic rock, used to aid moisture retention and ventilation in growing mediums.
Phosphorus (P): Vital element of plant nutrition: for root growth and ripening of fruits and seeds.
Pinching out or back: Training or shaping a tree by gently pulling off soft new shoots.
Potassium (K): Vital element of plant nutrition: for strong new growth, flower buds, and fruit. In horticulture, usually called potash.
Pot-bound: Describing a plant when its roots fill its pot and eliminate all air spaces.
Prostrate: Describing a plant that grows along the ground.
Pruning: Cutting or pinching back shoots, leaves, and stems to control growth and shape a plant.
Raceme: Elongated flowerhead made up of many individual flowers growing on their stalks from a central stem.
Repotting: Regularly removing a plant from its pot, usually every year or so, and replanting in fresh soil to encourage root growth.
Root pruning: Cutting back roots of a pot-bound plant to encourage growth of new roots.
Rootball: The mass of roots and soil seen when plant is lifted.
Root-over-rock style: With the roots trained over a rock, but growing in the soil.
Rootstock: Root system and main stem used as basis of new plant in propagation by grafting. The rootstock enables the new plant to grow strongly.
Saikei style: With rocks, sands, and small plants to look like a miniature landscape; also called a ‘tray landscape'.
Scion: A woody stem or a small section of plant, used in the propagation of a plant by grafting it on to a rootstock from another plant; the characteristics of the new plant are held in the scion.
Scorch: Foliage damage from strong sun or wind, or root damage from fertilizer overdose.
Semicascade style: With a trunk growing downward at a fairly steep angle so that it ends just at or below the pot rim.
Sinuous style: With branches growing from surface roots or other rooted branches in a randomly curving pattern.
Slanting style: With a straight trunk that leans up to 45 degrees from the vertical.
Species: Unit of classification for a plant that has particular characteristics; identified by the second word of its botanical name (e.g. Picea abies).
Sphagnum moss: Highly water-absorbent moss native to damp locations; used in air layering or to keep large wounds moist.
Standard: Tree or shrub with a single stem up to 6ft (1.8m) below the branching head.
Stock: see Rootstock.
Straight line style: With several, lop-sided branches growing vertically from a single fallen trunk.
Stratification: Encouraging tree seeds to germinate by dispersing them in sand and subjecting them to cold conditions before sowing.
Succulent: Plant with fleshy stem or leaves that can retain large amounts of moisture.
Subspecies: A unit of plant classification, for a naturally occurring variant of a species that has some similarity to the species.
Sucker: A shoot that grows out from a planf's base, above or below the ground.
Synonym: An alternative botanical plant name, usually an old or invalid classification.
Systemic: Describing an insecticide or fungicide that enters a plant's sap and, over time, counterattacks from within the pest or disease afflicting the plant.
Tap root: A long, anchoring root that grows vertically downwards in the soil; often, the first undivided root of a seedling.
Tender: Describing a plant that cannot withstand frost.
Tokoname: A region in Japan that is a major centre for the manufacture of bonsai containers.
Tufa rock: A very porous, water-retentive limestone, easily worked and so used for bonsai plantings.
Twin-trunk style: With a trunk split in two at the base.
Variety: The naturally occurring variant of a species.
Viability: A seed's ability to germinate.
Winter: kill Death of plant due to frost or freezing winds.
Woody: Describing a hardened plant stem that will not die off in winter or during dormancy.
Wound sealant: A compound that seals a cut in a branch or trunk to stop sap and moisture loss, and promote healing.
‘Yatsubusa': A particular dwarf form, with shorter internodal distances and more buds than usual, and denser top-growth.