I pride myself on being able to grow just about anything outside, but it’s practically a death sentence for the plants I bring in for the winter. The basics of watering, houseplant pests, and keeping them out of the kids’ reach, doom them from the start. I usually dig my favorite tender perennials, such as rosemary, lemon grass and scented geraniums, to theoretically save them until next spring. This year, they didn’t even make it until December before I killed them. I left them in their pots in the greenhouse during our long, warm fall, and then forgot about them. A sub zero cold snap got them before I did.

Houseplant Pests

When I do manage to keep a plant alive, I’m dismayed when theres an insect issue. But there are a whole slew of bugs that are happy to be inside, warm and dry with a ready food supply. Here are some of the worst free-loaders:

Aphids

Ah yes, our favorite little sapsucker. They can quickly weaken indoor plants making them look sickly in short order. When Im feeling particularly non-squeamish, Ill rub them between my fingers on the affected stems. If there are a lot of them, set them in your kitchen sink and hose off the stems and undersides of leaves with a vigorous blast of warm water.

Fungus gnats

A friend had a big issue with fungus gnats last spring on her vegetable seedlings. When we looked at the plants, there would be tiny black flies zipping here and there. Fortunately, fungus gnats dont do a lot of damage to the plants themselves (unless the larvae is feeding on the root hairs), but theyre not pleasant to have around. Bt (Bacillus thuringiensis) used as a drench on the soil works well to kill the larvae.

Whiteflies

These can cause damage to plants when the eggs hatch into nymphs, and the nymphs feed on the leaves. Although tiny, white flies flittering around the plants are a given sign of infestation, also look underneath the leaves to check for their presence.

There are several ways to handle whiteflies. For a minor problem, you can suck them up with a vacuum. Another option is to spritz them in the sink, or give them a spray of insecticidal soap. You can also set the plants outside on cold days. The tropical whiteflies wont live long in freezing conditions so its a balance of leaving the plant out long enough to affect the flies without harming the plant. If I did this, I would forget and kill what Im trying to save. But it does work. Just monitor your plant so it doesnt succumb to the cold, as well.

Spider mites

Spider mites are tough because they can crawl or be accidently moved to other plants they can even come in the house on the Christmas tree or other greenery. (Not that Im a fan of the artificial trees, by any stretch of the imagination!) Unfortunately, theyre also challenge to completely eliminate. Theyre very hard to see because theyre so small, but their presence is quickly known when you see webbing in between leaves or stems, particularly ones that look sickly.

Another way to spot spider mites is to place a sheet of white paper underneath the plant, and tapped on it. You might catch a glimpse of tiny, black spots falling on it. That is the tick-like mite. Spider mites prefer dry conditions, so increasing the humidity may help. So do washings and insecticidal soap dousings. At the worst case scenario, you need to toss the plant so it doesnt infect others.

House plants are great to help your indoor environment by greening your everyday living space. The trick is to keep the pests from taking up residence and to keep the kids from finishing them off. (Once I figure out how to do that, Ill let you know.)

The photo is copyright of alohaspirit through istock.