Despite all the care given indoor plants, it seems they do not respond. Indoor plants, like other plants, develop various pests that cause damages that range from nuisance to total destruction of the plant. These pests seem to defy the biological law against spontaneous generation. They seemingly appear from no where, but are introduced to indoor gardens with infested plant materials, on clothing or drift through the air.

Pest infestation should not be taken lightly. Indoor plants struggle to grow, and pests often make an attractive plant into a dead one.The first rule of pest management is to keep the pests out. Don't let your growing area become a vacation spot for pests. Successful gardeners are often besieged with "gifts" of ailing houseplants from well-meaning friends and neighbors. Avoid these hospital cases at all costs as they introduce problems that your plants have never experienced.

The second rule in successful pest management is to examine plants frequently. Close examination reveals potential pest problems before they get out of hand and cause serious problems. A small magnifying glass aids in the search for the smaller, less conspicuous problems.

The third rule of pest management is cleanliness. Use clean soil and clean pots anytime you plant or transplant your indoor companions. Give plants an occasional rinse of warm water or a quick bath in mild soap suds. Plant inspection cleanliness goes a long way in reducing pest problems. Even so, some pests require more stringent controls.

Common houseplant pests include spidermites, scale, white flies, mealybugs and aphids. Spidermites aren't insects but are minute pests related to spiders. They are difficult to see without a magnifying glass. Infested plants with spidermites develop numerous small windows or patches, and the leaves develop a grayish cast. The back side of the leaf has a dirty appearance and tiny webs can be seen on some leaves.

Scales are the armored tanks of the insect world. These insects are non-mobile. They are seldom, if ever, seen crawling on plants. The female covers the eggs and young with her armored shell so they are difficult to control.

White flies are tiny, white, butterfly-like creatures that fly when a plant is disturbed. The insects, as well as their tiny, bubble-like eggs are often seen on the underside of the plant.

Mealybugs form white powdery bits of fluff on the bottom of the leaves or in the joints of plants. Large drops of sticky honeydew may be present.

Aphids are sucking insects and produce large amounts of honey dew which cause a sticky appearance to the plants.

Other perennial troublemakers are fungus gnats. These are small, black flies that flit around houseplants as you water. They are generally a sign that a plant is overwatered. Let the plant dry between watering and don't allow moisture and soil to accumulate between the bottom of the pot and saucer as this is an ideal breeding area for the plants.

View Comments

If the pests are already a problem, the quarantine idea isn't going to work. Check plants carefully and diagnose the pest correctly. All but fungus gnats can be reduced by cleaning plants in soapy water. Sometimes cleanliness isn't enough and stronger methods are required.

Pests can be controlled by swabbing with rubbing alcohol. This works well if you are persistent and don't have too many plants. Larger outbreaks usually require sprays of some sort. Insecticide soaps (Safers and other brand names) are effective on most pests. Thorough and repeated coverage is essential. Under ideal conditions, some pests produce a new generation every seven days. If the outbreak is serious enough to spray once, spray at least two more times at 10- and 14-day intervals. Otherwise the adults are controlled, but new pests hatch from the eggs which are unaffected by the sprays.

Other houseplant sprays include pyretheum, Resmethrin, malathion and others. Don't make the mistake of using outdoor chemicals inside. Chemicals approved for indoor use are diluted and formulated to avoid odors and other potential problems. Read and follow all label directions. Certain products could cause serious damage to painted surfaces, carpet, upholstery or other furnishings. Spraying plants outdoors alleviates some problems, but that can not be done until temperatures are above 50 degrees.

Keep houseplant pests in perspective. Probably less than 20 percent of the problems are caused by pests. Most are caused by environmental stresses including temperature, water, light or nutrient extremes. True diseases, other than root decay, are rare on indoor plants and are best treated by discarding the plant. Treatment is expensive, time consuming and often does not work. As with anything else in the garden, new ones are easily propagated or acquired if the old ones are no longer attractive. Keep the pests controlled to enhance the health of your indoor plants and your enjoyment in growing them.

Join the Conversation
Looking for comments?
Find comments in their new home! Click the buttons at the top or within the article to view them — or use the button below for quick access.