Tomatoes - Questions & Answers

The tomato is the most popular garden vegetable in the United States. Tomatoes are fairly easy to grow but are susceptible to a number of problems. During the summer we receive many questions about tomato problems. The following are the most frequently asked.

Q. What causes the lower leaves of my tomato plants to roll up?

A. Leaf roll (curling of the leaflets) is a physiological condition that occurs most commonly when plants are trained and pruned. It should not affect fruiting or quality.

Q. What causes the flowers to drop off my tomato plants?

A. During unfavorable weather (night temperatures lower than 55°F or day temperatures above 95°F with drying hot winds), tomatoes do not set and flowers drop. The problem usually disappears as the weather improves.

Q. What can I do to prevent my tomatoes from cracking?

A. Cracking varies with the variety. Many of the newer varieties are resistant to cracking. Severe pruning increases cracking. Keep soil moisture uniform as the tomatoes develop and plant resistant varieties to minimize this problem.

Q. What causes small irregular, cloudy white spots just under the skin of my tomatoes?

A. These spots on green or ripe fruits are caused by the feeding of stink bugs.

Q. What causes the young leaves of my plants to become pointed and irregular in shape? I noticed some twisting of the leaves and stems after spraying the plants for the first time.

A. Judging from the description, it seems likely that your tomato plants have been injured by 2, 4-D or a similar growth-regulator weed killer. Never use the same sprayer in your vegetable garden that you use for weed control in your lawn. Drift from herbicides originating 1/2 mile or more away also can injure your tomato plants. For this reason, use extreme caution when applying lawn-care chemicals near vegetable or fruit plantings.

Q. What is a tree tomato?

A. The treelike plant sold as a "tree tomato," Cyphomandra betacea, is a different species from garden tomatoes. It is a woody tree that grows 8 feet or taller and bears after 2 years. The tree tomato is a tropical plant and does not overwinter outside anywhere the temperature drops below freezing. The fruits are small (1 to 2 inches in diameter) and are used primarily in stews or preserves rather than in salads. Some of the common, vigorous, indeterminate garden tomato varieties that are suitable for training and pruning (such as Ponderosa) are also sold as climbing or "tree tomatoes" by some seed stores.

Q. What is a "potomato?"

A. Although both potato and tomato plants can be intergrafted, the "potomato" (sometimes called "topato") commonly advertised is simply a tomato seed inserted into a potato tuber and planted together, producing both a tomato plant and a potato plant in the same hill. The results are not likely to be particularly successful.

Q. My grandpa grew a heart-shaped, dark pink tomato that was thick and meaty, yet juicy with great flavor. Grandpa’s gone and I can’t find a source for the seed. What can I do?

A. Fortunately, there are a number of seed exchanges like Seed Savers Exchange, RR #3, Box 239, Decorah, IA 52101, which have been finding and rescuing old varieties. More old and heirloom varieties are also available from conventional seed sources these days. Perhaps, by doing some homework and contacting one or several of these sources, you can find a variety that is exactly (or very nearly) like those you remember from your grandfather’s garden. As a guess, the variety sounds like one called Oxheart, which used to be fairly commonly offered and has recently become rare.

Q. Should you top plants late in the season?

A. You can remove the tips of tomato plants in late August since fruits that set after that time are not likely to ripen before frost.

Q. How do you save tomato seeds?

A. To save seeds, squeeze seeds and juice from fully ripe fruits into a container (do not add water) and let it ferment in a warm place for 2 to 3 days. Then rinse, dry, separate the seeds and store them in a tight container in a cold, dry place. Do not save seeds of hybrid cultivars since they do not breed true.

Q. What are determinate and indeterminate plants?

A. Several of the newer tomato cultivars are determinate (stop elongating early) because the main stem ends in a flower cluster after about four to five clusters. Fruit of determinate cultivars tend to ripen all at one time. They are good to grow when you need large quantities at one time - such as for processing. Plants of other cultivars are indeterminate (continue to elongate), with the flower clusters giving way to continued extension of the stems. Their fruits ripen throughout the summer. These cultivars are good to grow for fresh use. Determinate cultivars include ‘Springset,’ ‘Spring Giant,’ ‘Small Fry,’ ‘Campbell 1327,’ and ‘Heinz 1350.’ Indeterminate cultivars include ‘Early Girl,’ ‘Terrific,’ ‘Jet Star,’ ‘Better Boy,’ ‘Big Boy,’ and ‘Beefmaster.’

Q. What are the best varieties for tomato paste?

A. Tomato fruits with high solids and mild flavor - such as those from ‘Roma’ and ‘San Marzana’ - are often used for making paste, ketchup and sauce.

 

June 2000
Problem with Pines | Tomatoes - Questions & Answers | Plan A Cutting Garden | Bug Bites: Cucumber Beetles & Japanese Beetles | Hort Shorts | Hort Tips | Locally Grown: In Season Produce | Spotting Health Fraud | Foodborne Illness Peaks in Summer - Why? | Summertime Food Safety Guidelines | Health & Household Tips | Did You Know...

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