FAQ

Question

Q

I have black spots on my tomato plant leaves and some on the main stem. Will it kill the plant? Can I get rid of it? Will it apread to the soil or other plants? HELP. I see it in most of the greehouses I have been to. Is it to late to find someone with a place to find a clean tomato plant and still plant it and get fruit?

Answer(s)

A

Black spots on your tomato leaves and stem could be a fungal disease.  These are commonly called leaf blights or leaf spots. Below is a link to a picture of what the symptoms of this disease typically looks like.

http://www.umext.maine.edu/gardennews/images/Early%20Blight%20on%20Tomato%20Leaf.jpg

These diseases are promoted by cool, wet conditions like we had this spring. Fungal diseases can spread but there are a few things that you can do to help keep it under control.  If there are only a few leaves on your plants that are affected you can remove and discard them. In addition, water early in the morning so that the leaves of the plants will be dry before nightfall and let the soil dry out in between watering.  There are fungicides that can be applied but all will have restrictions on how many days between application of the fungicide and when the fruit is safe to eat.  If you choose to use one make sure to read the label and follow all of the directions carefully. As the weather clears up this problem will decrease. I have included a link on growing tomatoes that has more information. 

http://extension.usu.edu/juab/files/uploads/Horticulture/vegetable%20garden/tomatof.pdf

If this does not look like what is happening to your tomatoes you can bring a sample into our office at 2001 S. State Street #S1200 and we will help identify the problem.

Posted on 16 Jul 2009

Heidi Wayman
Horticulture Intern, Salt Lake County

Other Questions In This Topic