Old wood - a stem or twig on a bonsai that originated during the previous season's growth or at an earlier time.
Peat - partly decomposed organic matter; when it is used as an ingredient of potting soil it assists in moisture retention.
Perlite - a form of volcanic rock that is heat treated to develop a lightweight, coarse granule that when used as a component of potting soil has advantageous ventilation and water retention properties.
Phosphorous - another essential element of plant nutrition; identified by the chemical symbol P; aids in development of roots, ripening of fruits and seeds.
Pinching - is a technique used in bonsai cultivation of controlling and shaping the growth of foliage by pulling off soft new shoots with the finger and thumb in a pinching motion.
Potassium - the third essential element of plant nutrition; identified by the chemical symbol K; it encourages strong new growth, development of flower buds and fruit formation.
Pot-bound - the adverse state of a container grown plant where the root growth has filled the container to the extent of eliminating all vital air spaces.
Prostrate - the characteristic growth habit of a plant that naturally tends to grow along the ground instead of upright.
Pruning - the process of controlling the shape and growth rate of a tree by cutting back the shoots, stems and branches.
Raceme - a type of elongated flower that is composed of individual stalks all growing from a central stem; ex. Flower type found on wisteria trees.
Ramification - the dense branching structure of a bonsai that only develops after years of repeated pruning of the branches.
Repotting - the practice of replanting a bonsai tree at regular intervals to perform health maintaining tasks such as: root washing, inspecting, pruning, soil refreshing, and potting in a different or larger pot; all imperative to the health of a bonsai.
Rootball - the large mass of roots and soil visible when a tree is taken out of its pot or pulled from the ground.
Root pruning - the practice of cutting back the roots of bonsai in order to make room in the container for fresh soil and to encourage new root growth.
Rootstock - is the root system and main stem to be used as the base of a new tree when propagating through grafting.
Scion - is a small section of a tree, which contains all of the desirable characteristics of the parent tree that will be propagated into a new tree through grafting on top of the rootstock.
Shakan - a traditional Japanese bonsai style; also called slanting. Where the trees' trunk, appears similar to the formal upright style, but the trunk is slanting to one side.
Shari - an area where the bark and cambium have been removed from the trunk to suggest the struggle against fierce weather such as: wind, lightning, snow and ice
Species - the unit of classification for a plant with identifiable characteristics
Suiseki - stones that appear to look like large boulders or mountains and represent the spirit or essence of each; sometime used in a formal bonsai display.
Taproot - the large root of a tree that grows vertically downward, anchoring it into the ground; it is usually referred to in bonsai, because of its need to be pruned shorter or removed for container cultivation.
Tokonoma - a Japanese tradition of creating a specific area in the home where bonsai, accessory plants, Suiseki, and scrolls are displayed together in harmony.
Wound sealant - a number of compounds formulated to seal cuts made on branches or the trunk of bonsai to prevent the loss of moisture and promote heeling
Yamadori - trees collected from the wild, which have been shaped by nature alone and have been collected to be developed into bonsai.
Yose-ue - a traditional Japanese bonsai style; also called a group or forest. Where the trees are arranged in a container to resemble a group or forest of trees.
