| Word | Description |
| Acidity | How acidic or “sour” a soil’s pH is. |
| Air handler | The indoor unit that moves the air through the heating/cooling system. |
| Air Leakage (AL) | a rating that expresses the amount of air infiltration through cracks in the whole window |
| Air Plants | A plant that does not root in soil. It derives moisture and nutrients from the air |
| Algae | White, red, pink or grey circular patches that look like they are painted on the trunk of trees and shrubs. These are harmless and add color and interest to your landscape. |
| Alkalinity | How alkaline or “sweet” a soil’s pH is. |
| Aluminum/foil tape | Specialty tape with an acrylic-based adhesive that performs consistently under extreme temperatures. |
| Aphids | are soft bodied pear-shaped insects that suck juices from plants. They generally are less than 1/8 inch long and usually green in color but many are black, brown, pink, yellow, blue, or white. |
| Asthma | Asthma attacks all age groups but often starts in childhood. It is a disease characterized by recurrent attacks of breathlessness and wheezing, which vary in severity and frequency from person to person. In an individual, they may occur from hour to hour and day to day. This condition is due to inflammation of the air passages in the lungs and affects the sensitivity of the nerve endings in the airways so they become easily irritated. In an attack, the lining of the passages swell causing the airways to narrow; reducing the flow of air in and out of the lungs. |
