Written by University of Maine Cooperative Extension’s David Fuller
Tomatoes are one of the crops that is most often grown by home gardeners. Either in a sauce, sliced on a sandwich or as a caprese salad, it’s hard to beat a good, home-grown tomato.
And while they sure are tasty, tomatoes are prone to foliar leaf diseases that can render plants nearly leafless by the end of the summer. Here are ten tips towards better tomatoes:
•Don’t plant too early. Purple tomato leaves in the garden are an indicator that the soil is too cold. Planting about June 7 in the Farmington area is about right.
•Choose varieties that have disease resistance. This is your first defense against plant diseases. Some varieties even have late bight resistance!
•Use mulch. Black plastic mulch or straw are two good choices. Mulch helps keep higher levels of soil moisture and prevents disease spores on the ground from splashing onto the lower leaves.
•Remove the lower leaves when planting. It’s Ok to have just a few leaves at the top. Have you noticed how the disease process usually starts at the bottom leaves and works up the plant? Leaves should not touch the ground.
•Give the plants proper spacing. Spacing at 24 inches apart or even 30 inches if you have room allows good air circulation between plants. Plant diseases depend on high humidity and still air.
•Remove the suckers. These are shoots that arise from the crotch of a leaf where it joins the main stem. Don’t confuse with blossom clusters that arise above the branch crotch.
•Remove diseased leaves. The spores on the leaves will spread to other unaffected leaves and neighboring plants. Pick the leaves when dry and put in a plastic bag to dispose. Not in the compost pile.
•Search for and remove tomato hornworms when you first see their large droppings on the leaves and ground.
•Remove the topmost growing point of indeterminate (tall) varieties. Do this about the end of August. Blossoms in September will not mature in time before frost unless you use green tomatoes in a recipe. The energy from the plant will then go towards the other tomatoes to help ensure ripening.
•Water at the base of the plants, not overhead. Wet leaves provide good conditions for disease development.
For help with your tomato and other garden questions, please contact the University of Mine Cooperative Extension office at 778-4650 or email at extension.franklin@maine.edu
