It's Flu Season for Houseplants, Too

St. Paul, Minn. (January 1, 2001) - Ok, so houseplants don’t get the flu as we know it, but the winter months can make them more susceptible to a variety of diseases. To keep indoor plants healthy, following are some tips offered up by plant pathologists, scientists who specialize in diseases affecting plants.

Plants have been grown in homes for several thousand years, but not without a few problems, states plant pathologist Cindy Ash of the American Phytopathological Society. “Since plants didn't evolve in our homes, they aren't adapted to the environmental conditions that occur there, especially during the winter heating season.” She notes, however, that there are a few simple things that you can do to keep your houseplants green and growing.

Inspect a plant before you buy it. Don’t buy plants with leaves that are dried and brittle, have spots, or are yellowing or wilting. Look carefully for mites, mealybugs, scales, and aphids, which can resemble plant parts, often hide underneath leaves or on the leaf stems and may move when disturbed.

Put a new plant in a separate room away from other plants for a while. That way you avoid infecting your other plants with anything brought in on your new plant. If the plant still looks healthy after three or four weeks in its new home, you can move it.

Be sure your plant pot has good drainage. Excess water drowns roots and encourages root rot.

Make sure your plant gets what it needs. Not all houseplants are alike and many vary considerably with regard to moisture, temperature, and fertilization needs.

Clean the foliage. Dust and dirt can interfere with a plant’s natural processes. Every few weeks, clean your plants by putting them in the shower or sink and rinsing with lukewarm water.

Avoid temperature extremes. Placing plants near large windows, radiators, or furnace vents often creates more extreme temperatures than people realize and plants can tolerate.

Be careful about moving plants. For example, do not place a plant in a sunny south window if it has been grown in a less bright location, otherwise a white to brown burning of the leaves may occur.

Don’t mist your plants; it promotes disease. Use a humidifier or place pots on a bed of wet gravel if more humidity is needed.

The subject of this month’s feature story on the APS website is diseases affecting houseplants. For more information, visit APSnet. The American Phytopathological Society (APS) is a nonprofit, professional scientific organization dedicated to the study and control of plant diseases, with 5,000 members worldwide.