Glossary of Gardening Terms

Index D

Damp Down:
   To wet the floor and staging in a greenhouse to raise the humidity and lower temperature.
Damping off:
   A disease caused by soil-borne fungi, which rots the stems and roots of seedlings.
Day-neutral:
   Plants which flower in response to physiological maturity regardless of the length of the photoperiod.
Dead Head:
   To remove spent flower heads to prolong flowering and prevent self seeding.
Deciduous:
   Leaves etc. that are shed annually by the plant.
Decoction:
   Liquor or essence concentrated by boiling.
Decumbent:
   Growing close to the ground but with upwards growing tips.
Deep Water Aquatic:
   Plant that roots in a water depth of 30-90cm (12- 36 inches) and produces flowers at or above water level.
Dehiscent:
   Any dry fruit which splits open at maturity along defined lines or sutures to release the seed.
Deltoid:
   Triangular.
Depressed:
   Describes a solid flattened form.
Dentate:
   Toothed.
Dethatch:
   Process of removing dead stems that build up beneath lawn grasses.
Dibber:
   A pointed tool used to make holes in the soil for seeds, bulbs, or young plants.
Dichotomous:
   Dividing equally.
Dicotyledon (dicot):
   Any plant in which the seed has two cotyledons.
Dieback:
   Death of a shoot, beginning at the tip, due to damage or disease.
Digitate:
   Leaves with deep finger like lobes; palmate.
Dioecious:
   The condition of having all male or all female flowers on a single plant.
Disc Florets:
   Central part of flower head of members of the compositae.
Distichous:
   Two ranked, i.e. fruit, leaves etc. arranged in two lines on opposite sides of stem.
Diuretic:
   Exciting, or substance inducing, discharge of urine.
Diurnal:
   Activity that only takes place during daylight. e.g. a flower that only opens during the day.
Divide:
   To prepare a plant by splitting into 2 or more parts, each with its own root system and one ore more shoots.
Divided:
   Deeply cut into segments or lobes.
Dormancy:
   A general term denoting a lack of growth of seeds, buds bulbs or tubers due to unfavourable environmental conditions (exogenous or external dormancy ) or to factor within the organ itself (endogenous or internal dormancy).
Dot Plant:
   Usually tall growing plant used singly in the design of a formal bed or border to accentuate contrasts of height, colour/texture.
Double:
   Describes a flower with more petals than in the normal wild state and few, if any, stamens.
Double digging:
   Preparing the soil by systematically digging an area to the depth of two shovels.
Drainage:
   Of soil: well-drained, due to presence of coarse particles which permit passage of surplus water.
Drill:
   Narrow, straight furrow in the soil, used for sowing seeds.
Drip line:
   The imaginary circular line drawn on the ground around a tree at about the point where the branches reach furthest from the trunk.
Drupe:
  Fruit with outer skin, inner fleshy layer and central woody 'stone'; derived from a single carpel, usually one-seeded, in which the exocarp is thin, the mesocarp is usually fleshy, and the endocarp stony. (e.g., peach or cherry)
Dwarf:
   Small or slow growing variant of a species resulting from hybridisation or specific cultivation methods (as in bonsai)

Last updated 10 March, 2002
© copyright 1999, P. A. Owen