It's been the worst year ever for tomatoes, it was the perfect storm for late blight. The airborne disease thrived in the cool wet weather we had this year. It didn't help that plants were shipped from the south already infected with disease. I've fielded lots of questions about how to avoid the disease next year, and about what to do with the shriveled vines this season. Here's my best advice......as far as late blight's effect for next year I don't think we should worry. As long as the crops you were growing were above ground a hard freeze will kill the disease. If potatoes were affected underground, that's another story. If that's the case I would turn the soil over, add compost and leave it unmulched for the winter hoping for the cold to do its work.
So far I've been right about late blight, after it was discovered early in the season I felt it would become an epidemic as the season progressed and many gardeners learned about late blight as September rolled in. I'm guessing that next year will be just like any other year, but if we get the cool wet spring the best thing you can do is treat the new plants with an organic fungicide like Serenade. Once late blight does hit, it's over, the plants will eventually succumb to the disease. But remember there are other fungal diseases that affect tomatoes that don't kill the plant. If the fruit and stems turn black, that's late blight, but if the bottom leaves start turning yellow, that's something else, very common and really nothing to worry about.
As far as the vines left in the garden now, remove them and destroy them. The last place they should go is the compost pile. Bag them and send them to the landfill (breaks my heart to tell you that), burn them or bury them two feet deep.
Late blight is a reminder how powerful nature can be, and how powerless we are in the garden.
Lets hope for a better tomato season next year.