House plants are susceptible to attack by spider mites and insects. The worst of these pests can damage your plants appearance and health; however, some pests are merely an annoyance and do no real damage. After purchasing a house plant, it should be quarantined and inspected over a three-week period before placing it with other house plants, to help determine if there are pests present.
Powdery mildew is a common house plant disease that affects plants such as the jade plant, begonia, African violet and kalanchoe, according to Iowa State University. It appears as a white, dusty growth on the surface of leaves. The growth can appear in circular spots or cover the entire surface of the leaf. This mildew likes moist, cool locations, so keeping the plant away from cool drafts can prevent powdery mildew.
Root rot is another disease common to many indoor house plants. The leaves of a plant with root rot will wilt, turn yellow or droop. The roots will appear black or brown instead of white and the outer root will easily strip off. This disease likes warm, wet conditions. Make sure not to over-water your plants, and be sure use a potting mix with good drainage.
A common pest of several house plants is the greenhouse whitefly. The pest is commonly found on ivy, poinsettias, hibiscus and lantana. The bugs are somewhat gnat-like and covered in a fine white wax. Adults lay eggs on the leaves, and the eggs hatch in three to seven days. The eggs produce greenhouse whiteflies in the immature nymph stage, and most injury to plants is caused by the nymphs. Yellow sticky cards or tape can be used to trap adult whiteflies and vacuuming can also eliminate them. Yellow sticky cards can be purchased at most home improvement stores.
Mealybugs are soft-bodied bugs that suck the sap from plants, causing the plant leaves to shed. These insects can also excrete a large amount of sticky honeydew. Mealybugs prefer poinsettias, lantana, jade, holly, cactus and coleus. African violets and gardenias often get root-infesting mealybugs. To get rid of these bugs, make a diluted spray using one part rubbing alcohol to three parts water. Before using the alcohol on each plant, make sure to do a test patch so you will know whether or not the alcohol will harm your plant.