Q. How do I control pests on my houseplants?
Pest and disease control
Even well cared-for houseplants occasionally suffer a pest infestation. Here are six common houseplant pests and how to control them without resorting to toxic treatments.
Aphids: These small white, green, black, brown or orange pests are often found in clusters on tip growth and flower buds. A strong spray of water is usually enough to dislodge them—give an infested plant a good shower in your tub or outside with the hose.
Mealybugs: If you see tiny tufts of white cotton, usually clustered in sheltered areas of stems or on the underside of leaves, your plant has mealybugs. To control them, apply rubbing alcohol to individual mealybugs (the white tufts) using a cotton swab.
Mites: About the size of a grain of salt, mites are hard to see, but the damage they do is not. Look for mottled or stippled leaves, deformed flowers and very fine webbing over the damaged area. A strong spray of water will usually eliminate them—just be sure to spray both the tops and bottoms of leaves.
Scales: You won't spot scales easily as they blend in well against stems and leaves. The first clue of a scale outbreak is often sticky specks on a plant’s leaves or the tabletop. Check the leaves and stems directly above the sticky area for bumps that can be rubbed off. Rub off scales by hand—if there are too many, find a chance to put the plant outside where the scales’ natural enemies can get rid of them for you.
Whiteflies: If you notice white specks flying up when you brush against a plant, whiteflies have set up camp. To control them safely, get insecticidal soap and spray it on the leaves, particularly on the underside (try the spray on a few leaves before spraying the whole plant to be sure it is not sensitive to the soap).
Cats: Some cats like to dig in potted plants; others use them for litter boxes. If your cats won't stay away from your houseplants, crush some rue leaves and spread them on top of the soil—the scent is very unpleasant to cats.
Visit the following links for more information about plant disease and pest control:
Organic Gardening: Organic Houseplant Care
University of Minnesota: Houseplant Insect Control
North Dakota State University: Houseplant Care
Colorado State University: Managing Houseplant Pests
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service