<a title="View user profile." href="/author/editors">The Editors</a>Wed, 07/06/2016 - 11:46
It sounds like they might have Septoria leaf spot disease. Try to keep the foliage as dry as possible (avoid overhead watering) to limit the spread of spores; also remove the most disease-riddled leaves as well as any that have dropped into the soil. This is a difficult disease to manage once spores are in the soil. If the plants continue to succumb, consider replacing them next year with disease-resistant varieties (start with clean soil, i.e. remove what is there and replace with compost-rich, amended soil).
It sounds like they might have Septoria leaf spot disease. Try to keep the foliage as dry as possible (avoid overhead watering) to limit the spread of spores; also remove the most disease-riddled leaves as well as any that have dropped into the soil. This is a difficult disease to manage once spores are in the soil. If the plants continue to succumb, consider replacing them next year with disease-resistant varieties (start with clean soil, i.e. remove what is there and replace with compost-rich, amended soil).