The Wood County Master Gardeners were at the Wood County Fair earlier this month and were asked a lot of
the same questions from fairgoers.
Here are some of the answers to those questions.
Question: What is causing spots on my tomato leaves and why are they turning yellow?
Answer: There are two potentially serious diseases that can affect tomato plants. Early blight and
Septoria leaf spot are diseases that affect the leaves, stems and fruit of tomatoes.
Early blight is characterized by irregularly shaped brown spots on older leaves with the surrounding
tissue turning yellow. The spots enlarge and can cause the leaf to turn brown and eventually drop. The
fruit will be exposed to the sun and be susceptible to sunscald, a condition that causes dark, sunken
spots near the stem end of the tomato.
Septoria leaf spot is characterized by small circular spots on the upper surface of the lower leaves and
have a light colored center. Both diseases thrive during periods of hot, humid weather.
The best control of these diseases is prevention. Rotate crops every 3-4 years to reduce the buildup of
spores in the soil. Make sure your planting site has well drained soil and good exposure to the sun.
Space plants far enough apart to allow for good air circulation and water in the morning so the leaves
have a chance to dry. Mulching will also help keep spores from splashing onto the leaves and fruit.
Pruning and destroying leaves at the first sign of infection can help slow the spread of the disease.

Since both diseases can overwinter in your garden, it is important to practice good sanitation by
removing and destroying infected plants at the end of the season. Do not compost them.
If you choose to use fungicides, please read and follow label instructions carefully.
Question: How can I keep squash bugs from damaging my zucchini and summer squash?
Answer: The best time to control squash bugs are when your plants are young and flowering. Early
detection of eggs and nymphs is important as adult squash bugs are difficult to kill.
Regularly check the undersides of the squash leaves for eggs and crush them. You can remove and kill
nymphs and adults by dropping them in a pail of soapy water. This is effective if only a few plants are
affected.
You can trap squash bugs by laying out boards or pieces of newspaper. They will congregate underneath at
night and you will be able to collect and destroy them in the morning.
Remove plant debris from around the garden where squash bugs could potentially hide. In the fall, clean
up all plant matter to reduce the number of overwintering sites. Insecticides are normally not needed to
manage squash bugs but if you notice wilting early in the season, then an insecticide application may be
needed to manage them if you so choose.
When applying insecticides, be sure to get good coverage on the undersides of the leaves as that is where
most squash bugs are located. Please read and follow the label directions carefully before applying any
insecticide.
Got more questions?
The Wood County Master Gardeners will be in the commercial tent at the Pemberville Fair this week every
evening from 6 to 10 p.m. They will also be there on Saturday from noon to 10 p.m.
Volunteers will be on hand to answer any gardening questions. Feel free to bring any samples of pests or
diseases for diagnosis.
Brochures and information sheets will be available to help both the novice and experienced gardener
alike.