What do you use when you see hardening spots on the leaves? What causes it? And is there a way to prevent it?
The Gardener’s Answer
Hi, Kelli: It has been a difficult year for tomatoes! With the amount of rain and cooler temperatures earlier this summer it has not been great for tomato production. Tomatoes are susceptible to many different diseases. There are several different fungus that can infect tomatoes and we have seen a lot of that this growing season. It is difficult to say for certain what is going on with yours without seeing them. Are the entire leaves turning brown and crispy or are there random dark spots on the foliage? You can take a sample of your to the agriculture/horticulture agent(s) at your County Cooperative Extension Service or to a local garden center with a knowledgeable staff for a positive diagnosis and treatment options. When plants are not given optimal growing conditions they are more prone to other problems. Tomatoes require a minimum of 6 hours of direct sunlight and will grow best in a nutrient-rich, well-drained soil. Planting disease resistant-cultivars and providing optimal growing conditions can make all the difference in terms of growing healthy, productive plants. Always avoid overhead watering. Good air circulation is helpful in preventing diseases. If you have been growing tomatoes in the same space for several years, it may be time to rotate your crops. It is important to remove and dispose of all infected foliage and weed around the base of the plant. Sanitation is important during the growing season and in the fall so that insects and bacteria do not have a place to over-winter.
Kentucky Living-Ask the Gardener