Organic Control of Spider Mites

Spider mites attack a wide variety of plants, including some trees.

Spider mites are a common pest belonging to the same family as ticks, daddy long legs and scorpions. They are very small and, as they infest the underside of a plant's leaves, can often be missed with a quick glance over. Spider mites can cause severe damage to many plants, and their activity peaks in warm, dry periods. When spider mites attack vegetable and fruit plants, you may wish to consider using organic methods to control and eliminate their population. Such methods will accomplish this without exposing your crop to harmful chemicals.

Identification

Spider mites are difficult to see with the naked eye. They are small creatures with eight legs and a body reminiscent of a tick. Different species may exhibit different colors, though they often range from shades of red and yellow to brown or green. The two-spotted spider mite, which is a very common species, may be green or brown with two black or deep purple spots on its back.

Damage

The damage which spider mites may inflict on a plant varies depending on the species and season. Leaves commonly take on a dusty gray or bronze appearance as they become infested. The plant might appear overall speckled, and the leaves may wilt. In severe cases, leaves may fall off prematurely and the plant may die.

Method One

For an outdoor garden, you may consider introducing natural predators of the spider mites. These include lady beetles, pirate bugs and predatory thrips. There are many ways to do this, such as luring these predators with attractive plants, or purchasing them commercially. This method is ideal if you are attempting to protect non-crop plants, such as flowers and trees. Alongside this, reconsider the use of pesticides as these often kill the spider mites' predators, leaving plants unprotected and vulnerable.

Method Two

Eliminating the population on indoor plants is a bit trickier. Depending on the size of the plant, you may be able to hose off the infected plant in the sink or a shower. Wipe the leaves and stalks with a damp cloth that has a small amount of dish soap added to it. You should repeat this treatment once a week or bimonthly to help eliminate and control future populations.

Method Three

For greenhouse plants, crops and those in an area where you don't mind spraying, you can mix three tablespoons of dish soap into a gallon of luke warm water. Spray each plant thoroughly, making sure you don't miss any spots. Spider mites are small and an inconsistent job may allow a few of them to escape between water droplets to later repopulate your plant. Let the soap sit for a few hours, then hose off your plant. Alternatively, you can replace the dish soap with rubbing alcohol. This method is particularly effective if your plants also harbor aphids or white flies.

References

• Colorado State University Extension Service: Spider Mites
• Ever Growing: Houseplant Bugs & Pests
• Oregon State University Extension Service: Using Home Remedies to Control Garden Pests