Spider Mites

Spider Mites: Tiny Pests That Cause Big Plant Problems

Spider mites are common garden pests that can damage vegetables, flowers, trees and shrubs. Although often mistaken for insects, spider mites are actually arachnids, related to spiders and ticks. These tiny pests can be red, brown, green or cream-colored and usually live in colonies on the undersides of leaves. They also leave behind fine webbing, which is a key sign of an infestation.

Spider mites reproduce quickly, especially during hot, dry weather. Eggs can hatch in just a few days and mites can reach adulthood within a week when temperatures are above 85°F and humidity is low. Because they are so small, spider mites can be difficult to spot. One simple way to check for them is to shake a plant branch over a sheet of white paper. If mites are present, they will appear as tiny moving specks.

Early signs of damage include small yellow or brown spots on leaves. As feeding continues, leaves may turn yellow or bronze, dry out and fall off. This can greatly reduce plant growth and crop production. Plants commonly affected include tomatoes, beans, melons, strawberries, roses, azaleas and spruce.

Spider mites often target stressed plants, so keeping plants properly watered and fertilized can help reduce infestations and protect plant health.