Applying the spray: Read the label and follow directions exactly. Be sure the plant type you wish to spray is listed on the label. The chemical may damage the leaves if applied in too high a concentration, or if the plants are sprayed more frequently than recommended. Leaves may also be burned if aerosol cans are held too close to them when spraying. Do not spray in the sun, or when the temperature is higher than 85°F.
Applying insecticides: Spray both sides of the leaves, all around the stems, the surface of the soil, and the outside of the pot. A spreader-sticker will help to keep the spray from beading on waxy leaves and will help it penetrate the waxy shells of scale insects and mealybugs.
