What's happening to my basil?
The accompanying photos show my poor, puny basil plants about three days ago. They looked good -- glossy, dark green leaves, apparently in good health, then in less than a week, they commenced to look drab, somewhat desiccated, with discolored, puckered leaves. I've been attentive to watering, but not too much, and they're located in plenty of sun. I've used the same gardening and cultivation techniques I've used successfully in the past. "What's happening to my basil"?, asks this sad gardener, who loves to make pesto: fluky weather? climate change? insect attacks? airborne- or animal-transported herbicides? (We apply no chemicals on our plants).
From your photos, it looks as if the basil may be subject to downy mildew, a fungal disease. Go to our link and view photos and more information: Basil Downy Mildew