This week I had to pull over 30 heirloom tomato plants out of my garden that were covered with black fungus from stem to fruit. Not a single one even had a chance to ripen and I started most of these from seed back in February. We've had an excessive amount of rainfall in the Northeast this summer (only 9 days of sun in June) and extremely low temperatures throughout the season until just last week when the weather started to actually feel like summer with highs in the 80s and lots of sunshine. Until then, practically nothing was even growing in the garden, but the tomatoes looked nice and healthy and I had been pruning the suckers as they appeared. When I noticed the fungus I applied a copper-based fungicide and within 2 days everything was wilted and black. Now I seem to have contaminated soil, from what I've read and do not know what to do about it as it seems possible it will still be in the soil next year. How do I correct the soil situation so that this doesn't happen again?