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.