Common Houseplant Pests – Part 1

By: Jennifer LaMontagne – Assistant Horticulturist – Bloch’s Farm – Green Lake, WI

If you moved some of your plants indoors for the winter, you may have noticed leaves or buds dropping. Changes in environment, sunlight, and watering can affect your plants. Additionally, your plants may suffer from a variety of ailments including pesky pests such as mealybugs, spider mites, and aphids.

Houseplants are susceptible to mealybugs because of the favorable mild temperatures and the lack of natural enemies. A few common houseplants that are susceptible to mealybug infestations are dracaena, ferns, orchids, philodendron, and various herbs.

Mealybugs are off-white to almost pink in color and have flattened oval, segmented bodies. Mealybug eggs are small, cottony masses which can often be found beneath the leaves or where leaves join the stem. Mealybugs like dark places, so be sure to look for them under the leaves and well inside the foliage of a plant. It is a good idea to routinely check your plants to catch any infestations before they become severe A severe infestation may cause your plant to exhibit wilted, curled or yellowed leaves, as well as stunted growth. Mealybugs also excrete a sticky substance which can lead to sooty mold. To control these pests, clean off the insects and eggs with an alcohol-soaked cloth or cotton swab. Mist the insects with a mild soapy solution and repeat if necessary on a weekly basis. Insecticidal soap or neem oil can be used to control mealybugs to a certain extent. These treatments only affect the insects at certain stages in their life cycle.

For severe infestations, a systemic chemical would be most effective as this would be ingested by the insect rather than having to penetrate the mealybug’s waxy coating. To help prevent future infestations, avoid overwatering or overfertilizing, and wash the foliage regularly with a leaf shine product.

Stay tuned for next week’s article on two more common houseplant pests: spider mites and aphids.

Bloch’s Farm is not yet open for the season but we are busy getting ready for all your spring needs. Call 920-294-6000 or e-mail with any questions. You can also check our website online at and follow us on Facebook.

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