Hi folks. Sorry to read about your blight problems. Over here it basically has become impossible to grow tomatoes out in the open because of blight. Unfortunately fungal spores can travel for miles. So even if one has the cleanest garden ever one can still get this problem
. Part of the problem here is probably that commercial potato growers aims for earlier and earlier crops under horticultural fleece and then spores from their field eventually infects both potatoes and tomatoes in the garden at a much earlier time than what was usual in the past.
Only reliable organic option here is to grow tomatoes under glass and to make sure that the foliage never gets wet as that will prevent the spores from germinating. This usually works well over summer here, but when autumn comes one can still get a few problems because the humidity is so high. Of course here the summers are often cold so growing in a greenhouse is a good idea anyway. A simple plastic tunnel or similar would work just as well or probably even better for a warmer summer climate. While results never can be guaranteed, my suggestion would be that any protection that keeps the foliage dry would be worth trying.
