Houseplant Pest Identification

Regularly inspect houseplants for pests.

While houseplants are not as prone to pest infestations as outdoor plants, they are still sometimes troubled by insects. Often, houseplants are brought home from a nursery or store already infested. If houseplants stay outdoors during warm months, pests may attack them there. Pests can also climb inside through windows and screens. If pests are identified promptly, they are usually relatively easy to control. Does this Spark an idea?

Prevention

Before bringing any plant indoors, inspect it closely for signs of pests. The University of Minnesota Extension's Web site recommends isolating new or fresh-from-the-outdoors plants for two or three weeks. This gives insect eggs time to hatch, exposing pests before they affect several houseplants.

Another smart step is to wash houseplant leaves with water and a soft, moist cloth every few months, removing dust and grime that can attract insects. Keeping plants healthy by giving them the proper amount of light, water and fertilizer also makes them less prone to infestations. Repot houseplants every six to 12 months using fresh potting soil. This encourages good water drainage and healthy roots.

Stickiness and Mold

If the leaves or stems feel sticky or have black mold growing on them, it's likely the plant is infested with insects that leave excrement behind. This points to aphids, whiteflies, mealybugs or scales.

Poor Color and Mottling

If houseplants turn color and plant growth is reduced, pests could be the problem. Look for mites, aphids or thrips. Leaves with small yellow speckles can indicate an insect problem. Check for whiteflies, aphids, mites, scales or mealybugs. If the plant's leaves have grayish-brown discoloring, look for scales.

Holes

Houseplants with holes in the leaves are almost certainly suffering pest damage. Beetles, caterpillars, slugs or snails are probably the culprit.

General Malaise

Houseplants experiencing slow growth, droopy stems or leaves, or that have no obvious signs of disease may be infested with insects. Look for fungus gnats, maggots or springtails.

Treatment

Most houseplant pests can be either washed off or hand picked. For whiteflies, consider vacuuming with a handheld machine. Use sticky traps for flying insects. Make chemical control a last resort, and only use insecticides labeled for the specific type of pest that's a problem.

References

• Colorado State University Extension: Managing Houseplant Pests
• University of Minnesota Extension: Houseplant Insect Control
• University of Delaware College of Agriculture & Natural Resources: Insect Pests of Houseplants