Backfill: Fill in the hole made for a plant.
Bare Root: Usually shrubs and trees sold with no soil on their roots.
Bark Ringing: Taking of a circle to bark from a fruit tree to inhibit growth but to encourage cropping.
Base Dressing: Fertilizer or compost put on or dug in to the soil before planting or sowing.
Bedding Plants: Plants grown to almost full size and then planted out usually in summer to make colorful displays.
Bicolor: A plant with flowers or leaves with two distinctively different colors.
Biennial: A plant that goes from germination to seed bearing and death in two seasons.
Blanch: Excluding light from a plant to keep it soft, usually for eating.
Bleed: To lose sap through a cut or wound.
Blind: Failing to produce flowers or losing the growing tip of a plant through injury usually.
Bloom: Either the flower of a plant or a whitish coating on leaves or stems.
Bole: The part of a tree trunk from the ground to the first branch.
Bolt: Plants, usually vegetables, especially onions, that produce flowers and seed heads prematurely.
Bonsai: Refers to either the trees or the method of producing miniature trees by pruning roots and restricting the size of the container. Originated in Japan.
Bottom Heat: Heating plants by subsoil or under bench heating usually for germination or cuttings.
Bract: A modified leaf, sometimes protective at the base of a flower. When it is brightly colored, it can be mistaken for a flower petal as in the case of a poinsettia.
Break: A shoot growing from the axil on a plant.
Bulb: This is really a modified stem acting as storage for the plant (that’s why you shouldn’t cut the foliage back on daffodils when they stop flowering because it feeds the bulb). A true bulb is made up of individuals, although often tightly packed, scales. The term bulb is also applied wrongly to tubers and rhizomes.
Bulb Fiber: Special compost formulated for growing bulbs like hyacinths and narcissus.
Bulbil: A tiny bulblike structure, often found in a leaf axil.
Bulblet: A developing bulb formed on a mature bulb.