Tomato Troubles

By Marie Hofer, Gardening editor, HGTV.com

There comes a critical time in the summer when you think, I should be picking juicy, perfect tomatoes soon. If you've been unlucky, however, it just doesn't seem to be happening. Either the foliage is yellowing and looks wimpy, there are dark splotches on the leaves or the fruit has issues. Other than wondering if your neighbor planted enough to share, is there anything you can do?

Here are some common tomato problems—the signs, symptoms and solutions:

Blossom drop
Symptom: Blossoms drop and fruit doesn't form.
Why: Either temperatures are too warm or too cool (above 85 degrees during the day and/or more than 72 at night or below 55), and pollination suffers.
Solution: Most early-season varieties can handle a little chill. To help ward off too-hot blues in your tomatoes, get a heat-tolerant ("heat set") tomato. Keep taking care of the plant, and when temperatures improve, blossom formation and fruit set will resume. Next year you might want to consider getting heat tolerant varieties such as 'Suncrest' and 'Sunmaster'.

Blossom end rot
Symptom: A dark spot appears on the blossom end of the fruit and a brown, rough scar develops. The fruit begins to rot.
Why: Blossom-end rot often occurs when soil moisture is inconsistent, and the seesawing moisture levels in the fruit cause a calcium deficiency, even if the soil already contains plenty of calcium. Too much nitrogen fertilizer and excessive rain or irrigation combined with periods of drought are usually the culprits.
Prevention: Water regularly (if necessary) and provide mulch to help keep water levels consistent. Rarely, calcium deficiency is a problem: have your soil tested; in areas where pH is below 6, add limestone; where the soil pH is between 6 and 7, add gypsum.

Early blight
Symptom: The foliage has irregular, dark brown spots each with concentric dark rings inside, giving them a somewhat bull's-eye appearance. The spots become surrounded by yellow tissue. The bottom leaves are affected first, turn yellow and begin to drop.
Why: Early blight is a fungal disease that's usually brought on by frequent rain and warm temperatures.
Solution: Plant resistant varieties. Consult your local extension agent for appropriate fungicides and spray schedule. Don't compost the foliage.

Catfacing
Symptom: The fruit is malformed with some scarring; parts of the fruit appears to be cinched between bulbous protrusions.
Why: Catfacing is thought to be caused by any of a number of weather conditions, including cool, moist weather and prolonged heat. Contact with certain herbicides is also thought to be a problem.
Solution: Usually catfacing is most troublesome in the early part of the season and the tomato plant corrects itself as temperatures warm. Switch varieties next year.

Fruit Cracking
Symptom: The fruit cracks either in concentric circles around the stem or in lines radiating out from the stem.
Why: Tomatoes usually crack when excess moisture causes pulp and juice to form faster than the skin grows.
Solution: Water consistently and mulch to even out soil moisture.

Verticillium wilt
Symptom: Lower leaves begin to wilt; foliage appears mottled, the leaf areas between veins turning yellow, then brown.
Why: Verticillium wilt is a serious fungal infection that's sometimes encouraged by too much water and fertilizer. Once in the soil, it can stay there for years, so avoid planting susceptible plants in that location.
Solution: Plant resistant varieties. Don't compost the foliage.