|HAD LATE BLIGHT ON ALL MY TOMATOES MID SEPT. REMOVED GREEN TOMATOES AND DISCARDED ALL PLANTS IN TRASH. DO I HAVE TO TREAT SOIL FOOR NEXT YEAR? I DO NOT USE CHEMICALS IN GARDEN.|
|Early Blight is caused by the Alternaria fungus. It overwinters on infected plant material, even seeds, so it's hard to completely remove the spore reservoir from the garden by cleaning up all the vines and fruit. Early Blight works slowly, whereas Late Blight (caused by the Phytophthora fungus) may kill plants within a week. This fungus is always growing somewhere and releasing spores into the air, which moves on wind currents. It doesn't overwinter in your soil, so you won't need to worry about it attacking your plants next year, especially if you purchase disease resistant tomato plants or seeds.
If you are growing tomatoes in the same site every year, the soil could use a break from constant monocropping, but if you don't have room for a second plot, I suggest loading up the soil with good compost. Compost contains lots of helpful organisms which can work against disease organisms. Work a few inches into the existing soil, and then spread several inches on top of the soil as a barrier mulch. Once your tomatoes are planted, mulch with straw as well. Keep your plants healthy so they'll be in top condition to resist disease.