Common Problems When Growing Tomatoes and Suggested Solutions

Problems May Occur When Growing Tomatoes

Allen Robinson: Ask A Master Gardener

Sunday, May 12, 2019

Q: My family loves to eat fresh tomatoes off the vine, but I hear that growing tomatoes around here is a challenge. Can you tell me why it is difficult to grow them here and what I can do about it? Stacy H., Tulsa

A: You are certainly not alone both when it comes to loving tomatoes fresh off the vine as well as having trouble growing them in northeast Oklahoma.

One of the most common issues is known as “blossom drop,” which occurs from incomplete pollination. Weather is the chief cause of inadequate pollination in garden-grown tomatoes, with the most important factor being temperature. Effective pollination stops occurring once night temperatures are consistently over 75 degrees and/or when daytime temperatures are consistently over 92 degrees — especially if it is windy. Too much rain or too high or low humidity are additional weather factors which reduce pollen fertility. Also, overapplication of nitrogen fertilizer leads to blossom drop as well as tall, lanky plants and other diseases.

The solution to this is to plant very disease/pest resistant and healthy plants as soon as possible after the last frost has occurred. Then, pick the fruit as soon as it turns pink and let it continue to ripen indoors. Do not let it sit on the vine until it becomes overly ripened and soft.

Another common issue is called “blossom end rot,” where the fruit develops blemishes on the blossom end of the fruit. This is caused by a calcium deficiency in the plant when the fruit is young. Overwatering, either from nature or the gardener, is the most common cause rather than the lack of calcium in the soil. Keep the soil evenly damp as much as possible.

Skin splitting, called “cracking”, is also caused by plants going from too little to too much water. Be consistent about watering. Mulch plants to provide consistent moisture and temperature at the root level. Be careful to not mulch directly against the plant trunk as it can lead to diseases.

Speaking of diseases, avoid splashing soil on the plant and onto tomato fruits, as this carries related fungi and bacterial diseases. Instead, use either a soaker hose or drip irrigation system, or carefully water at the base of the plants. Avoid damaging tender roots by not hoeing too deeply or too closely to the plants.

In addition, there are several pests that love to live off the stems and leaves of tomato plants. For a listing of pests and how best to battle them, go online to tulsamastergardeners.org and search for OSU Fact Sheet EPP-7313 (Home Vegetable Garden Insect Pest Control).

Experts will say that the best weed control in a lawn is to simply grow a healthy, thick lawn which tends to crowd out weeds. The same is true for vegetables. Look for high quality varieties at reputable nurseries around town and ask which varieties are the most disease resistant. There are many varieties available.

Tulsa’s climate is a challenge to growing tomatoes in the summer. But, with a little attention to the details, you can have very good success. And, remember, there’s always fall.

 Garden Tips

• Don’t spray insecticides during fruit tree bloom or pollination may be affected. Disease sprays can continue according to schedule and label directions.

• Mowing of warm-season lawns can begin now. Cutting height for bermudagrass and zoysia grass should be 1 to 1½ inches high, and buffalograss 1½ to 3 inches high.

• Harden off transplants outside in partial protection from sun and wind prior to planting.

• Let spring flowering bulb foliage remain as long as possible before removing it. That will allow the energy from the leaf to flow back into the bulb for flower production next year.

• Prune roses just before growth starts and begin a regular disease spray program as the foliage appears on susceptible varieties