Connecticut Garden Journal: How to control common houseplant pests
Sitting around the dining room table surrounded by houseplants in the dead of winter is a satisfying feeling. We even have some of our geraniums blooming in the sunny, South-facing window.
But upon closer inspection things aren't all well in the houseplant jungle. We're not the only ones appreciating the greenery this time of year.
I see little black flies flying around my houseplants. These are most likely fungus gnats. Although they look ominous, they generally don't harm our houseplants. The larval form is mostly interested in feeding on the potting soil's organic matter. They hatch into adult black flies that lay eggs in the potting soil and the cycle continues. They can be annoying though. To control them, repot the houseplant with fresh potting soil, cover the potting soil with a layer of sand to dry out the eggs or use an organic, yellow sticky trap in the pot to catch and kill the adults.
I also notice some white, cushiony growth on the backside of some fig leaves. This is most likely mealybugs. They suck the plant juices from leaves causing them to yellow and they drip a sweet, sticky honeydew substance on rugs and furniture. Control this pest by dabbing individual insects with a cotton swab doused in rubbing alcohol.
I've even spied some green and black aphids on the new growth of our herbs. These soft-bodied insects also suck plant juices and drop honeydew. They're simple to control. Move the infected plants to a warm garage or basement and spray with insecticidal soap or Neem oil. This usually stops aphids in their tracks.