What’s the difference between early blight and late blight?
A. Early blight, Alternaria solani, is a common fungal leaf spot disease encountered by most Maryland gardeners. Early blight can infect tomato leaves early in the growing season and is favored by warm, humid weather. Septoria leaf spot is another fungal disease, like early blight, that can cause leaves to turn brown and die. As you can see in the photos below these two diseases produce very different leaf symptoms and they rarely affect stems or fruits. Late blight can occur at anytime during the growing season when the weather is cool and wet. The disease is slowed down by a return to hot, dry weather.
