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Tomatoes susceptible to several diseases, insects
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An endless list of issues may cause tomatoes not to produce well. Some of the common problems and remedies are as follows.


If tomatoes are planted too early, cold snaps and cool night temperatures may affect the early blooms. It can hamper pollination and sometimes cause blooms to drop off. It is always a good idea to plant late April to early May.

Always plant tomatoes in a sunny location with eight hours of full sun. Move the plants around from year to year in different places. It keeps soil-borne disease and insect infestations down.

Based on the rain in North Georgia this spring, it is good to fertilize again. Many nutrients have been leached out of the soil more quickly this season.


Leaves begin to yellow on older plants, and they turn dry and fall off. Leaves on the lower stems curl upward if it is verticillium wilt. With fusarium, the lower leaves turn yellow, wilt and die. Then the upper shoots wilt and eventually die. Both can be diagnosed by slicing the stem lengthwise near the soil line and examining the tissue. The color will be tan to dark brown.

Unfortunately no chemical or fungicides will control either. Destroy the plant and remove it.

Blossom end rot

This common problem can be avoided easily by testing the soil before planting for sufficient pH.

If the pH is too low, the plant is not getting enough calcium. A foliar application of calcium chloride can help if the problem has started. Spray it directly on the plant and fruit. To prevent blossom end rot, start spraying when the green tomatoes are about the size of a silver dollar and spray once a week for four weeks.

Soil, water conditions

If you have compaction, drainage problems or low or high pH, it will have a significant effect on the plants. Having a soil pH range between 6.5-6.8 is best.

Tomatoes need deep roots to thrive, so water deeply and consistently, keeping the soil at a consistent moisture level. Do not water them every day. Instead, use soaker hoses with a good, slow drip and water them once or twice a week for good root development if it does not rain.

Raised beds are an ideal way to control soil and drainage problems.

Cracking, catfacing

Tomatoes may crack and become misshapen during warm rainy periods. Again, keep the moisture supply as even as possible. Look for crack-tolerant varieties of tomatoes.

Catfacing is another kind of cracking or scarring in which tomatoes develop unusually fast and swell. This is not a disease, rather a result of cooler weather. Do not to spray herbicides near the tomatoes as they are highly susceptible to damage from herbicide drift.


Many insects feast on tomatoes, such as tobacco hornworm, whiteflies, flea beetles, mites and aphids. Check for insect damage regularly, especially on the bottom of leaves. If you suspect insect damage, bring a sample to the local extension office for a diagnosis and recommendations for control.

Insecticidal soaps and products with carbaryl can be used. Also, a bacterial insecticide (Bt) can be effective in reducing insect populations.

Some insects spread diseases and viruses, so check for resistant varieties hybridized to be tolerant of certain pests and diseases. Good varieties to look for are early Cascade, Roma, Better Boy, Beefmaster and Big Girl. Always check the labels for the abbreviations VFN. This refers to verticillium wilt, fusarium wilt and nematode resistant varieties.

Wanda Cannon serves as Master Gardener coordinator and horticulture assistant for the UGA Cooperative Extension office in Hall County. Contact her at 770-535-8293, Her column appears biweekly and on

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