How to Apply Malathion to Tomatoes

Malathion helps keep tomatoes bug-free.

Tomatoes are one of the most popular home garden plants, but they can be tough to grow. Humans aren't the only ones that think tomatoes are delicious. A number of garden pests prey on tomatoes. If left uncontrolled, an insect infestation can ruin a tomato crop. One way to control these pests is with malathion pesticide. Regular spraying will stop aphids, spider mites and other predatory insects in their tracks.

Things You'll Need

• Spray bottle

Instructions

1. Wait until the weather is mild and there is no rain forecast for 24 hours before spraying.

2. Mix malthion concentrate at a rate of 3 teaspoons per gallon of water. Pour the mixture into a spray bottle or garden sprayer. If using a pre-mixed formula already in a spray bottle, move on to Step 2.

3. Spray the tomato plants to thoroughly coat the foliage, just before the point of run-off. Concentrate on spots underneath leaves and the space between stems where insects like to hide. You can begin treating tomato plants for insects as soon as one week after transplanting.

4. Re-spray the tomato plants at one-week intervals -- no sooner -- as needed. You can continue spraying up to the day before harvest.

5. Wash your hands thoroughly after each herbicide application.

Tips & Warnings

• Do not allow children or pets into your tomato garden until the malathion has dried.

• If your tomato leaves develop brown spots, the plant may be suffering from malathion poisoning. Discontinue the malathion and use another product instead.

References

• University of Minnesota Extension: "Fresh Market Tomatoes"; Arthur E. Gaus; October 1993
• PBI Gordon: Malathion (PDF)
• North Dakota State University Extension: Garden Insect Control Guide
• Clemson Cooperative Extension: "Tomato Insect Pests"; Randall P. Griffin, et al.; November 1999