Plant Science Terms - B

Bacillus thuringiensis - bacterium used as a biological control agent for many insects pests

Balanced fertilizer - fertilizer containing equal parts of each major element, such as 10-10-10

Bacterium - single-celled, microscopic organism having a cell wall but no chlorophyll. Reproduces by cell division

Balled and Burlapped (B&B) - plant dug with soil. The root ball is enclosed with burlap or a synthetic material. Typically larger trees or shrubs that were grown in the ground at a nursery are dug when ready for sale, wrapped in burlap material, and then sold.  More recently these plants contain wire baskets in addition to being wrapped in burlap

Band - to apply a pesticide or fertilizer in a strip over or along each crop row

Bare-root - plants, usually trees and shrubs, with little or no soil around its roots; deciduous plants and small evergreens are commonly sold bare-root. Some perennials are also sold as bare root plants

Bark - all tissues outside the vascular cambium of a woody stem

Basal - at or near the base of a branch or trunk; in some cases, at or near a plant’s crown

Basal break - new growth that develops at the base of a branch or near a plant’s crown

Beneficial fungi - fungi used in controlling organisms that attack desirable plants

Beneficial insect - an insect that helps gardening efforts. These insects may pollinate flowers, eat harmful insects, parasitize them, or break down plant material in the soil, thereby releasing its nutrients. Some insects are both harmful and beneficial. For example, butterflies can be pollinators in their adult form but destructive in their larval (caterpillar) form

Berm - mound or wall of earth

Berry - fleshy fruit of cane fruits, bush fruits, and strawberries

Biennial bearing - producing fruit in alternate years

Biennials - plants that produce foliage the first year, flowers the second year, and then dies at the end of the second growing season.  These plants require 2 years (2 growing seasons) with a dormant period in between seasons to complete their life cycles

Binomial - biological species name consisting of two names: the genus name and specific epithet

Biological control - reducing pests by utilizing other organisms. For example, controlling gypsy moths by using Bacillus thuringensis, a disease that affects the gypsy moth and is readily available in garden centers

Biological insect control - use of beneficial organisms to control pest insect populations

Biosolids - by-product of wastewater treatment sometimes used as a fertilizer, also known as municipal sewage sludge

Blackleg - darkening at the base of a stem

Blade - flattened, green portion of the leaf and also the flat portion of the grass leaf above the sheath

Blanch - to exclude light from plants or parts of plants to render them white or tender. Often done to cauliflower, endive, celery, and leeks. Also used to promote adventitious root formation on stems

Blend, seed - combination of two or more cultivars of the same species, for example Rebel and Falcon tall fescue

Blight - extensive and rapid death of plant tissue (leaves and other plant parts)

Blotch - blot or spot (usually superficial and irregular in shape) on leaves, shoots, or fruit

Bole - see Trunk

Bolting - going to seed or flowering prematurely, usually due to heat. Plants will produce a flower stalk and seeds, and then die before the end of the season. Lettuce and other crops will bolt during very hot summer temperatures. Leaf crops are discouraged from bolting by removal of flower heads. (See also Deadhead.) 

Bonsai - one of the fine arts of horticulture; growing carefully trained, dwarfed plants in containers selected to harmonize with the plants. Branches are pruned and roots trimmed to create the desired effect

Botanical insecticide - an insecticide, such as rotenone or pyrethrum, derived from a plant. Most botanicals biodegrade quickly. Most, but not all, have low toxicity to mammals

Botanical maturity - in fruits, refers to a final stage of development when the fruit is still on the plant and cell enlargement and the accumulation of carbohydrates and other flavor constituents are complete

Botany - science that studies all phases of plant life and growth

Botrytis blight - commonly known as gray mold or fruit rot. This gray, felt-type mold (fungal disease) is promoted by cool, moist weather and will cover parts of a plant causing stunting, dieback, and distorted growth

Bract - modified leaf, usually small, but sometimes large and brightly colored, growing at the base of a flower or on its stalk. Clearly seen on dogwoods and poinsettias

Bramble - spiny cane bush with berry fruits (e.g., raspberries and blackberries)

Branch - part of the tree that arises from the trunk and supports shoots, twigs and leaves

Branch collar - see Collar

Break - any new growth coming from a bud.; see Bud break

British thermal unit (BTU) - amount of heat required to raise the temperature of 1 pound of water 1°F

Broadcast - sow seed by scattering it over the soil surface; to apply a pesticide or fertilizer uniformly to an entire, specific area by scattering or spraying it

Broadleaf evergreen - non-needled evergreen

Broadleaf plants - dicot plants with leaves that have a flat, relatively broad surface as distinguished from plants with needle- or scale-like leaves. Broadleaf can be evergreen or deciduous and also written as "broad-leaved"

Brown rot - soft rot of fruit covered by gray to brown mold

Bryophytes - plant scientists recognize two kinds of land plants, bryophytes (nonvascular) and tracheophytes (vascular). Bryophytes are small, non-vascular plants, such as mosses, liverworts, and hornworts. They play a vital role in regulating ecosystems because they provide an important buffer system for other plants, which live alongside and benefit from the water and nutrients that bryophytes collect

Budding - type of grafting (asexual plant propagation) in which a non-fruitful, vegetative scion (one bud) is placed in a stock plant

Bud break - resumption of growth by resting buds

Bud head - swollen or enlarged area where a bud was grafted to a stock

Bud leaf - first emerged leaf of a grass plant

Bud scale - modified leaf that forms a protective covering for a bud

Bud sport - see mutation

Bud stick - shoot or twig used as a source of buds for budding

Bud union - suture line where a bud or scion was grafted to a stock. Sometimes called a graft union

Buds - undeveloped stem, sometimes enclosed in protective scales, consisting of a tiny bundle of cells, from which leaves, lateral buds, flower parts or all three grow. It is also a general term to refer to bulbs and bulb-like structures (corms, tubers and rhizomes.)  These plants grow from an underground storage unit of some type. Bulbs can be both hardy and non-hardy

Buffer capacity - maximum amount of either strong acid or strong base that can be added before a change of one pH unit occurs

Bulb - budlike structure that consists of a below ground stem with closely crowded fleshy or papery leaves or leaf bases that contain stored food. An example would be a tulip

Bulbil - small bulblike organ that sometimes forms on aerial plant parts

Bulblet - miniature bulbs that develop from meristems in the axils (base) of scaly bulbs; underground bulb formed in the leaf axis on a stem

Bunchgrass, bunch-type growth - plant development in the absence of rhizome and stolon production; a non-spreading grass


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