This past growing season I had severe problems with leaf rot. It went after my winter and summer squash, zucchini, melon, cucumber, bush and pole beans, romaine lettuce, radicchio etc. Is there anything I can do this fall and winter to go after the spores in the soil.
For me, the first thing that comes to mind, is soil building. I believe a healthy soil, will give you healthy plants. So continue to work on the soil. I would also cover all the beds / rows with a heavy blanket of mulch.
During the growing season, I would also keep a heavy mulch around your plants. This will keep soil from splashing onto the foliage while raining. No overhead watering, for the same reason. Water in the morning, so the foliage will dry out during the day.
Space plants farther apart. Good air circulation.
Seed selection, choose varieties that are right for your climate and desease resistant.
DDF summed it up pretty good. I think that mulching will go a long way in preventing thin next year. You can mulch will all kinds of materials: hay, grass straw, etc. They all have their advantages and disadvantages. You will want to apply enough to make sure that you don't get dirt splashing up on the leaves.
For the long term, however, you will have to improve your soil with the addition of more organic matter. This will, in turn, add more beneficial microbes which (now, this is purely my theory) I think will help to suppress the harmful microbes that cause the leaf rot.
You are already doing this when you mulch since the mulch will break down and decompose into the soil. Also, the addition of a compost pile would be beneficial as well. Once you have compost, you can add more beneficial microbes to the soil through the addition of compost tea. You can learn more about the benefits of this "tea" by reading the ACT sticky in the Compost Forum.
Thanks guys you did clear up one thing for me; the spores aren't coming from the leaf mulch. I did think it was a possibility.
I have been composting since the fall of 2006. I have 2 fixed plastic composters, and have just made 2 hardware cloth composters 12 1/2 feet in circumference by 3 feet high. They are both presently full, and I'm building my monster leaf pile.
My procedure in the garden is to allow seedlings to grow tall enough to accommodate 2 inches of leaf mulch. However, since summers here in middle Tennessee are hot and dry, I cut a 2 inch trough between the rows and bury a soaker hose before mulching. This makes watering easier and more efficient, and it sure makes the soil cooler.
It went after my winter and summer squash, zucchini, melon, cucumber, bush and pole beans, romaine lettuce, radicchio etc. Is there anything I can do this fall and winter to go after the spores in the soil.