Leaf Curling on Houseplants

Pests

• Common pests, including aphids, spider mites, mealybugs and scale insects cause the foliage of an otherwise healthy houseplant to discolor, wilt and shrivel up within days. Using their piercing mouthparts, the tiny, noxious pests suck plant sap from plant parts, reducing overall health and vigor. Severely damaged leaves fail to regain natural color and drop prematurely. Pests such as aphids and spider mites secrete honeydew, a sticky substance that serves as the breeding ground for sooty mold. Take the infested houseplant outside and douse it with a spray of water from a hose. Alternatively, treat larger pest infestations with rubbing alcohol or a registered insecticide.

Sunlight

• Exposure to direct sunlight causes the foliage of indoor plants to appear curled and shriveled. Initial symptoms of excessive sunlight exposure include curled leaf tips and edges. Unless remedied, the entire surface of the leaf wilts, turns brown and dries up. Move the houseplant a few feet back if it is placed too close to a window, or consider hanging a lightweight or sheer curtain on the window to provide it dappled light. Conversely, lack of light, especially during the winter, may cause leaf curl. In such a case, provide the plant supplemental lighting to keep its foliage healthy.

Drought

• Improper watering practices increase stress on a houseplant, causing its foliage to curl, turn yellow and eventually fall off. Although the water requirements of houseplants vary, the plants typically thrive in evenly moist soils. Container soil dries out sooner, requiring frequent irrigation as opposed to garden soil. Water the houseplant thoroughly whenever required, until excess drains out through the holes in the base. Avoid using very cold or hot water, but provide the plant lukewarm water to prevent shock.

Other Factors

• A number of diseases cause curling foliage on a houseplant, including powdery mildew, fusarium wilt, cankers and leaf curl. Although prevention is the best method of control, treat infected plants with a registered fungicide to control spread. Overwatering a plant prevents its roots from absorbing oxygen and spreading it to different parts, causing root rot, a condition that includes such symptoms as curled or distorted leaves. Excessive fertilizer and salt buildup can also cause the leaves of indoor potted plants to curl.