Bacillus thuringiensis (Bt)—A bacterial disease sold under brand names such as Dipel, Thuricide, Bioworm, Caterpillar Attack, etc. A nontoxic way to kill caterpillars.
Bagworms—Insects that build baglike cocoons on conifers and other plants.
Balanced fertilizer—A fertilizer that contains, in equal or nearly equal proportion, some measure of the three primary fertilizing elements: nitrogen (N), phosphorus (P), and potassium (K).
Balled and burlapped (B & B)—A method of packaging plants and trees with a ball of soil around the roots, wrapped in burlap.
Bare root—A method of packaging dormant plants having no soil around the roots.
Biennial—A description of the life cycle of certain plants which require two years to produce seed.
Black spot—Leaf and stem fungus that primarily attacks roses.
Bonsai—Japanese meaning “to cultivate in a tray.” An Oriental art of growing dwarfed, carefully trained miniature plants. The purpose is to create a tree or landscape in miniature.
Border planting—Any plant or group of plants which acts as a barrier or boundary to segregate sections of a property.
Borers—Very damaging insects whose larvae bore holes in trees. A sure sign of plant stress.
Bract—Leaflike plant part, sometimes colorful, located below the flower or on the stalk of a flower cluster.
Bulb—Any plant that grows from a thickened underground structure. A true bulb is more or less rounded and composed of fleshy scales that store food.