Careful Monitoring Controls Houseplant Pests

Last Updated on July 10, 2020 by Kimberly Crawford

Want to keep your houseplants healthy? Check frequently for problem insects and wash them away with a soap and water bath.
If you haven’t done so yet this season, check your houseplants for unwelcome pests. Those that summer outdoors will require extra attention, but even those that stay inside can harbor insects.

Wash the pots and foliage with mild, soapy water. Use a mild soap such as Ivory, not a detergent. If you suspect a severe insect infestation, you can use an insecticidal soap such as Safer’s or another similar product.

To wash small plants, wrap a cloth around the stem and over the edges of the pot to hold the soil in place. Then turn the pot over and dunk the plant in mild, soapy water. Rinse in clear, lukewarm water.

Repotting in clean soil often will physically remove insects that otherwise would travel indoors with your plants. If you don’t wish to repot them, let the soil dry out completely before watering. Humidity loving insects will either die or find a new home.

Remove discolored or dying leaves and stems, and you’ll remove a potential hiding place for insects.

how to control houseplant pests

Identifying Specific Pests

#1. Aphids

aphids on houseplants

Wilting plant tips are a sign of aphids. Look for clusters of these tiny, green or black insects near the soft, growing parts of the plants.

Aphids multiply rapidly, and for much of the year bear live young without mating. You can watch the births with a hand-held magnifying glass before you wash the aphids away.

#2. Mealybugs

mealybugs on houseplants

Look for bud drop and foliage damage. Mealybugs have soft, oval bodies and produce cottony fluffs over themselves. Look for them on the undersides of leaves in leaf axils.

Read also: Get rid of mealybugs on succulents

#3. Mites

mites on houseplants

Look for fine webs and mottling on plant leaves. Mites themselves are extremely tiny, the size of dust specks. They also spread easily, traveling on hands and clothing or in puffs of air.

#4. Scale

scale on houseplants

These light-colored insects look just like their name implies. The light-colored scales sometimes have hard-shelled bodies. On the plant, they often look like a growth or fungus.

#5. Whiteflies

whiteflies on houseplants

When disturbed, they fly around the plant like swirling bits of dust. Whiteflies easily develop resistance to insecticides.

Ants are attracted to the sweet honeydew secreted by aphids, mealy bugs, scales, and whiteflies. Ants nesting in the pot must be repeatedly flooded. This works best when you provide a drier home nearby.

Place a bucket of compost next to the infested pot. Place a stick bridge between the two containers. Once the ants have all left the flooded plant, you can dump the compost outdoors.

Insect Pest Controls

The simplest and safest method of controlling insects is a soap and water bath. Aphids, mealy bugs, mites, and young scales all can be washed away. Those that remain will be more susceptible to disease outbreaks because of the higher humidity in their immediate environment.

You can dislodge adult scales with an old toothbrush, a toothpick, or a cotton swab. Dip the cotton swab in alcohol to rub away aphids or mealy bugs. A bath in weak alcohol and water solution will kill large infestations without harming most plants. If you think your plant might be sensitive to alcohol, test a leaf with a mild solution and wait a few days to see if any damage appears.

Dormant oil spray, available at garden centers and hardware stores, is a nontoxic control for mealy bugs, young scales, and spider mites. The spray is safe for most plants. Do not use it on epiphytic plants such as the comet orchid, or on delicate ferns and hairy leafed gesneraids such as African Violets.

Chemical insecticides should be used as a last resort on indoor plants. Choose a spray formulated for indoor use and apply according to label directions.

Garden insecticides such as Sevin or malathion may be used. However, use half-strength or weaker solutions. Take the plant outdoors to spray and allow it to dry before bringing it back in.

Never spray indoors where ventilation is inadequate. Be sure the wind carries the spray away from you, not onto you. Wear protective clothing and gloves. Mix only as much insecticide as you need, and dispose of any leftovers according to package directions.