I’ve been in contact with gardeners in both the Saratoga Springs and Moreau Community Gardens who are experiencing tomato troubles.
The main question was how to distinguish between Septoria Leaf Spot and Early Blight and what to do.
The problem on this plant is Septoria Leaf Spot and the solution is extreme cleanliness and careful watering.
A Septoria Leaf Spot shows itself as many small spots on the lower leaves of the plant. The spots get larger, have dark borders, tan centers and often a halo of yellow. Infected leaves wither and die and often drop off onto the soil. Don’t leave these leaves in the garden. Prune off infected branches plants, pick up infected leaves and throw them in the trash not the compost bin.
The best way to control Septoria is to clean thoroughly and water only at the bottom of the tomatoes. Don’t let water splash around as you will spread the disease.
Another good strategy is when you plant in the Spring, leave room around tomatoes for good air flow. That will help keep fungal issues in check.
Some of you have asked how to tell if it is Early Blight. These spots have a grayish cast with a dark border and appear on the stems and fruit as well as leaves. Look carefully at the spots, if there are concentric rings (like a target) in the spots then it is Early Blight.
Early blight infects tomatoes, potatoes, and sometimes eggplant and peppers.
Another gardener discovered a tomato hornworm on her plants. This hornworm had white, capsule-shaped eggs protruding from its back. She left it in the garden. She did the right thing.
The hornworm was carrying the eggs of a parasitic wasp. As they mature, the wasp’s larvae literally eat the hornworm eradicating not only this hornworm but future tomato destroying hornworms as well.
They are a gardener’s friend!