Glossary of gardening terms - D:

Damping off
A plant disease caused by fungi that makes small seedlings wilt and fall over in the ground soon after they break through the soil.

Deciduous
A plant that sheds its leaves in autumn.

Decking
Boards or plywood nailed to joists to form the deck surface.

Defoliation
The unnatural loss of the plant's leaves, usually to the detriment of the plant's health.

Die back
Death of the plant's stems which begins at the tips. Causes include lack of water, nutrient deficiency, unsuitable climate, severe insect, mite or disease injury.

Dividing
The process of splitting up plants, roots and all that have begun to get bound together. This will make several plants from one plant, and usually should be done to mature perennials every three to four years.

DIY
Do It Yourself. Rather than purchasing an item ready-made, or having a custom item made by someone else, the DIY project involves assembling and/or constructing something from parts and materials purchased, collected, and/or fashioned by the hobbyist.

Drainage
Movement of water through the soil in the plant's root area is vital in order that it grow. Fast drainage is typical of sandy soils, while slow drainage is typical of clay soils.

Drip line
The circle which would exist if you drew a line below the tips of the outer most branches of a tree or plant.

Dust
A chemical product in the form of a fine powder that is sprinkled on affected plants in order to eradicate insects or disease.