This spring my tomatoes suffered from early blight. I managed to get it under...
This spring my tomatoes suffered from early blight. I managed to get it under control and the tomatoes did okay and even bore some good tomatoes. Now they are looking like they are suffering from late blight. I am concerned about the blight carrying over into next season. Aside from cleaning up all parts of the tomato plants this fall and moving the location of the tomatoes next year, is there anything else I can do? Is there a way to treat the soil to kill the blight? Also, will tilling the garden in the spring spread the blight all over? Any advice on how to prevent it from coming back next year would be very much appreciated. Thank you!
Ramsey County Minnesota
Blight diseases are common and discouraging but there are some things that you can do to stay ahead of the game. You have already identified some good cultural practices. If you are able to rotate the planting areas this is great...just allow about 4 years for the spores to die off, and don't plant similar crops in that area (such as eggplants, potatoes, peppers or other solanaceous plants) because they will perpetuate the problem.
One of the most important things you can do is to plant blight resistant cultivars.
Another good practice is to mulch the tomatoes. This helps conserve water, keeps the soil evenly moist and prevents the blight spores from reinfecting the plants when water splashes up from the ground.
Even though we can't control the rain water, when you use the hose do not sprinkle water on the leaves. A well placed soaker hose would be the best way to water your tomatoes....again to avoid splashing the spores up into the plants.
Maintain good spacing between the plants so that they are well ventilated. A full-sun location is best.
Keep that area - both the beds and the surrounding area free of weeds. Many weeds are a good harbor for blight spores.
Tilling the soil should not spread the disease. Just don't translocate the infected soil into your uninfected planting areas.
You can chose to use fungicides but they should be considered preventative, rather than curative. Be vigilant about the weather conditions that may be favorable for blight and apply the appropriate chemicals right away.
Here are a couple of links that explain these two different blight diseases:
I hope this information is helpful. Please contact AaE again if you have further questions.