How to Get Rid of Mealybugs on Your Houseplants—and Prevent Them From Coming Back

Mealybugs are one of the most common pests that houseplants encounter. These insects damage plants by feeding on their sap, which often results in yellowing leaves, stunted growth, and even plant death. A mealybug infestation can be identified by a white, waxy residue on your houseplants. While a mealybug infestation can be worrisome, it is possible to treat. To keep your plants safe from these sap-sucking insects, we spoke to gardening experts who shared their tips for preventing and getting rid of mealybugs.

What Are Mealybugs?

A part of the Pseudococcidae family, mealybugs are easily recognized by their white, waxy, cotton-like material. The slow-moving, oval-shaped insects feed on the sap of plants, reducing plant health and overall vigor. "They excrete their waste, called honeydew, which is a sticky, clear liquid," says Rachel Schnaitman, associate director of horticultural operations at Longwood Gardens. "This liquid often causes mold, called sooty mold, to grow on the plant—further damaging and reducing plant health."

How to Get Rid of Mealybugs

If you've spotted a white, waxy coating on your houseplants and have identified it as a mealybug infestation, there are a handful of ways you can get rid of this pest.

Alcohol

One easy way to get rid of mealybugs is with rubbing alcohol. "Soak a cotton ball with no more than 70 percent isopropyl rubbing alcohol and wipe it on the mealybugs on the plant," says Carrie Spoonemore of Jackson & Perkins. "Be sure to test it on one leaf before applying the alcohol to the whole plant to ensure the alcohol doesn't burn it."

Neem Oil

Neem oil is a vegetable oil that's effective at getting rid of mealybugs. "Dilute 2 to 4 tablespoons of neem oil concentrate with 1 gallon of water and add the solution to a spray bottle," Spoonemore says. "Before applying the solution to the entire plant, test out a patch to ensure it will not kill the plant." Once you know it's safe to apply, spray the neem oil solution on the entire plant, including underneath the leaves. Repeat this process after a week or two if the infestation continues.

Insecticidal Soap

Insecticidal soap can be used to treat many common houseplant pests, including mealybugs. "Dilute the insecticidal soap with water. Start with adding 1 teaspoon of soap at a time, and add more depending on the severity of the infestation," says Spoonemore. Pour the solution into a spray bottle and apply it directly to the foliage, paying close attention to the underside of the leaves where mealybugs commonly hide.

Predatory Insects

There are several types of insects that can naturally kill a mealybug infestation. "These include lace bugs, parasitoid wasps, and a beetle known as the mealybug destroyer," says Spoonemore. "Introducing predatory insects is more commonly used for outdoor infestations or in greenhouses." You can purchase predatory insects from commercial online retailers—but reserve this method for outside plants only.

DIY Spray

Alternatively, you can make your own spray to treat mealybugs. To do so, combine a bulb of garlic, a small onion, and 1 teaspoon of cayenne pepper in a blender and blitz into a paste. Next, add 1 quart of water to the paste and allow it to steep for at least an hour. "After steeping, strain the mixture through a cheesecloth and add 1 tablespoon of liquid dish soap," says Spoonemore. "Add the mixture into a spray bottle and apply it to the plant and infestation." This homemade mixture lasts for up to one week in the refrigerator.

Rinse Mealybugs Away

If you're dealing with a light infestation of mealybugs, rinse your plants with water to dislodge any bugs. Simply place your plant in the sink or shower and run a stream of lukewarm water, making sure to spray the tops and undersides of the leaves.

Prune Your Plants

If you have a heavy infestation, you can try pruning away plant parts where the mealybugs live. Get rid of the plant cuttings immediately, as the mealybugs can survive on the parts of the plant you removed so long as moisture is present. Note that in many cases, it's best to discard plants with heavy mealybug infestations.

Causes of Mealybugs

Mealybugs are commonly found in houseplants and are attracted to plants with soft growth and high nitrogen levels, says Spoonemore. For this reason, it's important to avoid overwatering and over-fertilizing your plants.

Mealybug infestations often spread by bringing an infested plant home from a nursery and placing it in close proximity to your other houseplants. "They can live in the roots and spread from plant to plant, feeding off of growth points," Spoonemore says. Common houseplants that may encounter a mealybug infestation include aglaonema, coleus, cactus, dracaena, ferns, ficus, hoya, jade, orchids, palms, philodendron, schefflera, poinsettia, and various herbs.

How to Prevent Mealybugs

To prevent mealybugs, ensure that your plants are healthy, and not weak, under-potted, or stressed when you bring them home from the nursery. "Always carefully examine all new plant purchases for infestations before bringing them into your home," says Spoonemore.

Proper care will also help prevent mealybug infestations. "Reduce watering and fertilizing and wipe foliage regularly," she says. "If you have an infected plant, it is vital to quarantine it to prevent the spread to other plants."