Acid, alkaline—Descriptions of soil or water pH. Number 7 being neutral. A pH above 7 indicates alkalinity, and a pH less than 7 indicates acidity.

Aerate—Punch holes in, or loosen soil in order to allow better air circulation.

Annual—Plants which reach maturity in one growing season. The seed germinates; the plant grows, blooms, seeds, and dies within a year or less. Plants that have to be replanted each year in our climate are also referred to as annuals (e.g., marigolds).

Aphids—Small insects of assorted sizes and colors, usually oval in shape, which damage plants by sucking, plant juices.