What Creates Wilting in Plants?
Wilting plants causes alarm in the garden, but it's usually nothing a bit of water won't solve. If watering doesn't restore your plants, consider other causes of wilting. With quick intervention, you can probably save plants, although wilting is fatal in some cases.
The most obvious cause of wilting leaves is hot weather and inadequate water. When temperatures soar, plants cope by curling their leaves or wilting to reduce the total leaf surface area exposed to the sun. If leaves bounce back as cool evening weather arrives, they're fine. Leaves that remain wilted at night indicate drought or possibly another problem. Keep soil evenly moist and use natural mulches to conserve moisture. Don't use gravel or rock mulches, which collect heat. Give plants their preferred growing conditions. For example, grow vegetables in full sun, but plant shade-loving annuals, such as impatiens, where they're shaded by trees or buildings.
Numerous diseases can cause wilting, but you'll likely see other signs of problems as well. Fungi, for example, cause wilting in addition to leaf curling, cankers and rots. Bacteria, such as fire blight, may cause wilting, distorted growth and blackened leaves and branches. To prevent diseases, space plants so air circulates freely. Avoid watering in the evening and use soaker hoses rather than overhead sprinklers, which dampen leaves and spread disease. Avoid working in the garden when it's wet and remove or treat diseased plants immediately.
Leaf-sucking insects, as well as burrowing insects and beetles, can cause wilting leaves. You'll likely notice other symptoms as well. Aphids leave a sticky substance known as honeydew on the leaves and ground, while you may actually spot burrowing insects and beetles. Treat aphids and other small, leaf-sucking insects by spraying plants with a firm shot of water every other day. If water proves ineffective, try insecticidal soap or horticultural oil. Pick off large insects and drop them in a bucket of soapy water or treat them with rotenone or pyrethrum. Use pesticides as a last resort and follow all directions carefully. Spray pesticides in the evening when bees are less likely to be around.
Herbicides often do as much harm as good. If they make their way onto plants, they cause wilting, distorted growth and yellowed leaves. Depending on the severity of the poisoning, plants may survive and eventually resume growth. In some instances, plants die and your only option is to remove them and replant.
- Utah State University Extension: Plants Get Heat Stressed, Too
- Sunset: Disease Prevention
- "The Garden Primer," Barbara Damrosch
Julie Christensen is a food writer, caterer, and mom-chef. She's the creator of MarmaladeMom.org, dedicated to family fun and delicious food, and released a book titled "More Than Pot Roast: Fast, Fresh Slow Cooker Recipes."