The resurgence in popularity of houseplants will have many wondering
what to do to keep their plants heathy over the winter. Houseplants really
benefit from a “summer vacation” outdoors, but with the arrival of cold
weather, it’s time to bring them indoors. Aphids, mealybugs, scale, and
other houseplant insect pests aren’t normally a problem when potted indoor
plants are outside, but they can quickly become a major infestation when
they piggy-back on your plants back indoors.
Most houseplant experts recommend de-bugging your houseplants before
bringing them indoors for the winter. Soaking the pots in a tub full of warm,
soapy water for 20 minutes, using a mild liquid dishwashing soap, will
eliminate any bugs in the soil. Put some of the soapy water in a spray bottle
to douse the foliage, or generously splash the leaves and stems, too. Then,
rinse off the plants with a hose after removing from the water, and let each
pot drain completely. For larger houseplants, you can pour soapy water into
the pot to thoroughly soak the soil, spray the foliage, then rinse with a hose.
(If you’ve already brought your plants indoors, this can all be done in a
bathtub, shower stall, or laundry sink.) I wipe off the leaves to clean them
while damp, using paper towels, as well as clean off the pots.
Even with the most fastidious cleaning to eliminate insect pests, it’s
impossible to completely ensure that you won’t have problems. So, I
always treat my houseplants with a systemic insecticide, one that’s safe to
use indoors. A systemic insecticide is any pesticide that is absorbed into a
plant and distributed throughout its tissues. It kills any insect pests that
attempt to feed on the plant. The main ingredient is usually a neonicotinoid,
harmless to people and other mammals, but suspected of harming
honeybees and other pollinators. Since pollinators won’t be present
indoors, I’m comfortable using it on my houseplants during the winter.
Applied as a drench (dissolved in water and poured into the pots), one
treatment will be effective till spring. There are different brands of systemic
insecticides available at garden centers or online.
Healthy houseplants are enjoyable companions for gardeners through the
cold winter months ahead.