Trouble in tomato paradise

Hot days and nights have changed the happenings in my garden. After inches and inches of rain have fallen, I finally had to water all the containers of herbs on the deck and top off the whiskey barrel water garden. The refrigerator is full of cucumbers ready to be turned into pickles and before long I will need to consider starting some batches of chili sauce.

After a walk in the garden I have noticed some changes in the bottom leaves of my tomato plants. But my biggest problem continues to be the wildlife that visit the garden and take samples of tomatoes. This morning we watched a doe helping herself to ear corn in the front field. The juvenile rabbit in the front yard no longer hops away when I walk to get the mail. Ah, life in the country.

Have you been checking for pests and disease in your landscape and vegetable garden? If you sense “troubles” in tomato paradise you should consider visiting the website and reading up on tomato leaf spot diseases.

Septoria Leaf Spot is a fungal disease that affects the foliage of tomatoes. It does not affect fruit directly. The disease causes rapid defoliation when weather is warm and moist. Septoria Leaf Spot produces lesions that are usually brown, circular, and small with a yellow halo. Fungal fruiting bodies know as pycnidia can be seen usually in the middle of the mature lesion as tiny, black dots.

Septoria starts on the lower leaves and works its way up the plant. OSUE Fact Sheet, Septoria Leaf Spot of Tomatoes (HYG-3112-96 at, provides gardeners with important tips to control Septoria: 1) Rotate out of tomatoes for four years, 2) Deep plow, preferably in the fall, to bury all plant refuse, 3) Grow tomato transplants in sterilized soil, 4) Control weeds, especially horse nettle, Jimson weed, and nightshade, and 5) Use of a protectant fungicide may be necessary to adequately control Septoria Leaf Spot when conditions are favorable for disease development. Remember to read all and follow all directions carefully.

Septoria lycopersici lives between tomato crops in the soil on infested debris of tomato and weeds. Spores formed on crop debris splash onto foliage and start the disease. Wind and rain spread spores produced in the dark bodies formed in leaf spots to adjacent uninfected leaves. The fungus is most active between 60 and 80 degrees F when rainfall is abundant.

Many leaf spot diseases can mimic each other in their early stages of development, so careful observation is very important when determining what may be affecting your tomato plants. Proper diagnosis will help you select the most appropriate management of the disease.

Some other diseases that might threaten your tomato crop include: Early Blight, Late Blight, Bacterial Spot, Blossom-End Rot, and Blossom drop without fruit set. If you would like to learn more about these special problems with tomatoes, be sure to check out the OSUE FactSheets found at

I love to eat sun-warmed tomatoes right off the vine. My husband prefers carrying the salt shaker to the garden for his tomatoes. Do you salt your tomatoes or not?

Don’t forget to email your gardening questions to OSUE Brown County Master Gardener Volunteer Mike Hannah at

By Faye Mahaffey

Faye Mahaffey is an OSU Master Gardner volunteer.