How to Use Tomato Fungicides

Tomato plants can develop fungus.

Many gardeners love to grow tomatoes. They are relatively easy to grow. However, in wet, warm weather, tomatoes can become infected with fungus. Fungus spores invade the plant tissue and damage the stems and flowers. The fungus looks like circular marks with gray centers surrounded by dark rings. By treating tomato plants with fungicides regularly, you can prevent the spread of damaging fungus spores. No one fungicide is effective against all types of fungus. To get the best protection, use both chlorothalonil and Topsin M.

Things You'll Need

• Plant sprayer
• Fungicides (Topsin M and chlorothalonil)
• Garden gloves
• Protective eyewear

Instructions

1. In a plant sprayer, mix chlorothalonil fungicide with water according to the directions on the package.

2. Spray the leaves of the tomato plant, also covering the stems and flowers.

3. Apply the chlorothalonil mixture once every week.

4. In the plant sprayer, mix Topsin M fungicide with water according to the package directions.

5. Spray the leaves, stems and flowers of the tomato plant.

6. Apply the Topsin M mixture once every 10 to 14 days.

Tips & Warnings

• Cut off infected leaves. This should slow the spread of the fungus.

• If your spraying schedule calls for treatments of chlorothalonil and Topsin M at the same time, you can combine the two fungicides in the plant sprayer, rather spraying them separately.

• Always wear work gloves and protective eyewear when spraying fungicides.

References

• Plant Answers: Vegetable Fungus Disease
• NC State University Cooperative Extension: 2011 Foliar Fungicide Spray Guide for Tomatoes in North Carolina
• Iowa State University: Control of Tomato Blights in the Home Garden
• Tomato Tips: What Fungicides Work on Tomatoes