How to Grow: Tomato Blight Controls

Watch this video to learn about the various types of tomato blights and how to prevent them from killing your tomato plants in summer.


For anyone growing tomatoes in the Northeast, Southeast or in the Midwest you know about tomato blight. Tomato blight is kind of a big term but actually it could be any number of different diseases that attack the foliage of tomato plants. It could be septoria leaf spot, early blight, late blight or even bacterial speck. The signs are very similar for a lot of these. They start out as little spots on the leaves then slowly expand turning the leaf yellow and eventually the leaf will just die.

If you get this disease early in the season it can spread throughout the plant and you really cut back on production. Spores from a lot of these diseases lie in the soil so if you can actually create a barrier between the soil and the plant what will happen is that when it rains those spores won’t splash up onto those bottom leaves and get the disease started. That barrier could be a number of different things. It could be black plastic mulch. It could be hay. It could be straw or untreated grass clippings. The idea is to create a little bit of a barrier so when it rains you don’t get that splashing and that’ll slow the onset of the disease. Your plants will
probably also get it, but not as bad.

You can use some sprays. There’s certainly a copper spray and there’s one that I really like it’s called Serenade. It’s actually a bacteria called Bacillus subtilis. It fights the fungus that causes a lot of these blights. With this spray or with the copper spray, the key is to actually spray it before you have the problem. Once you have the disease it’s not really going to stop it. But if you spray it on the healthy foliage it will prevent it from spreading to those places. Spray and then reapply it after a rain is a good way to slow it all down.

If you have late blight disease on your plant what to do is pull it out of the ground put into the garbage bed and send it away. Don’t keep it in the garden. If you get any sprouts coming up from potatoes that you didn’t harvest last year or in the spring with some little sprouted tomatoes, pull those out too. Late bite can be very devastating in a garden so you want to get rid of it. A lot of these other diseases such as early blight, septoria leaf spot, bacterial speck… for those simply clean up the garden really well in the fall add compost to that soil. Also, do some nice crop rotation and that will actually help slow down the beginning of these tomato blights.

So using disease-resistant varieties and doing some cultural sanitation around the plants are good ways to get great tomato crop without losing a lot of it to blight. Also, grow disease-resistant varieties of tomatoes. Use disease resistant varieties to prevent the blight. You also can plant plants further apart unlike this situation where it’s a big jungle which creates an environment for a lot of these diseases to get started. If you plant further apart you have good air circulation and you have less disease.

Go here for more on tomato blights.

Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors