Controlling house plant pests

In many parts of North America and other areas of the world gardeners have traded their backyard gardening for indoor houseplant gardening. Bringing some plants in from outdoors, and tending to others that are indoors all year round.

Every home owner who keeps houseplants will encounter, at one time or another the dreaded house plant pests. Little bugs that you can often barely see that start to suck on the leaves or burrow into the stems and cause parts of the plant or the leaves to die. If measures aren’t taken to eradicate these pests quickly a whole plant could die.

There are only five major groups of insect and mite pests on house plants, they are very difficult to control and highly persistent, once established. Not only that- but many types of house plants re sensitive to pesticides when they are used on them, plus pesticides used indoors can be quite dangerous to the home owner, small children and household pets.

The three steps to controlling pests are:

Step 1 . Know how to recognize at least the major insect and mite pests that attack foliage plants: aphids, mealybugs, scale insects, whiteflies, and spider mites.

Step 2. Prevent the introduction of pests into the home or existing plant specimen arrangements:
a) buy or propagate only pest-free plants;
b) keep new plants separated from other plants for 4 to 6 weeks to see if any pest problems develop;
c) carefully inspect all plants at least weekly for signs of insects and mites.

Step 3. If a plant is found to be infested with insects or mites:
a) isolate the plant from other plants;
b) correctly identify the pest;
c) determine and apply appropriate control measures;
d) keep the plant separate from others until all evidence of infestation is eliminated, which may be several weeks or more.

Take Control

There are three popular general methods for treating house plants infestations: physically removing the pests and or washing the plant, general purpose ready to use sprays, and chemical concentrates for preparing spray mixtures.

Physical removal is easy enough for large pests- slugs, caterpillars etc.. Pests can also be swabbed with a small brush or cotton tipped applicator moistened with rubbing alcohol.

You may also opt to rinse or wash plants with a diluted mix of dish detergent soap or an insecticidal soap. Sometimes just placing a plant in your shower stall and gently spraying them with lukewarm water on the tops and undersides of the leaves is enough to rid the plant of an infestation, plus give it a good drink and flush it’s substrate at the same time.

Often the soap sprays or rinses need to be repeated over a period of time to totally rid the plant of pests. I also try to isolate plants that I find are infested – I’ll move them several feet away from uninfected plants at the very least, and often into a totally different room if it’s possible. There’s nothing worse than having several plants infested with pests at the same time.

In your garden centres you’ll find ready to use sprays, but if you go searching for one of these types of sprays make sure it’s labeled that it’s safe for use on house plants. Always read the labels and precautions on any of the ready made sprays that you are planning on using as some sprays are effective only for certain types of insects, while others are only effective when the pests are in certain stages of life.

Whiteflies are very difficult to control with standard sprays, but easily controlled with other sprays that are made specifically for whiteflies. Be sure to follow directions. There are many individual products on the market; be sure to read the label to determine which one to use.

Chemical concentrations are available to mix with water for application with a hand sprayer or mister. Insecticides and/or miticides are available separately or in mixtures. Generally insecticides will not control mites, and miticides will not control insects. Only the appropriate pesticide is needed. The wrong one will not be effective.

Another way to prevent infestations in the first place is to care for the plant properly. Many people end up having white fly and mite infestations on their plants in the winter time. The air is dry in the house and the plants are not kept moist enough. Misting the plants with water sprays a couple times of day or keeping the room they are in adequately humidified should help lower the chance of pest infestations in some plants.