This is the time of year when many gardeners are harvesting tomatoes. Associated Press gardening expert Jessica Damiano recently reported about the many pictures of strangely shaped tomatoes sent to her from fans of her gardening advice. She said people sometimes question if the tomatoes are okay to eat.
The good news, Damiano said, is that there is nothing wrong with the deformed fruits. Unless otherwise diseased, they are perfectly good for eating. Their unusual appearance does not affect their taste or nutritional value.
What's going on here?
If you have ever cut open a tomato, you know they are divided into internal parts, called locules, which contain seeds and a substance called gel. Most tomatoes have about four or five locules; other kinds of the fruit, like cherry tomatoes, contain two or three. Plum or Roma tomatoes have two locules.
But when a plant experiences temperature extremes, cell division in the developing fruit can go off track. Temperatures over 32 degrees Celsius during the day and 27 overnight can lead the tomato to form an extra locule. But there is not enough room inside a tomato for the extra part, so it grows on the outside of the fruit.
Not every tomato on an affected plant will be deformed, however.
What are the chances?
“Under the right conditions (temperatures that are too hot or even too cold), this could affect one or two tomatoes per plant, depending on where they are in the development process and what the (weather) conditions are,” said Timothy McDermott. He is an assistant professor and extension educator at Ohio State University.
The likelihood of one of your tomatoes developing a locule oddity is estimated to be about one in a thousand, McDermott said.
Any tomato can grow an extra locule. But, Damiano noted, heirloom kinds seem more likely to have this genetic mutation than hybrids.
The extra-locule mutation is not the only abnormality caused by extreme heat. Conditions including sunscald, blossom drop, halted fruit formation and ripening can also arise when plants are grown outside their usual temperature limit.
Provide shade for your plants when temperatures are predicted to remain above 32 degrees Celsius for several days. Attach a piece of 40 to 50 percent shade cloth to stakes inserted into the ground around the plant. Leave it in place from 12 to 4 p.m., when the sun is at its strongest. Then remove it to avoid problems caused by a lack of sunlight.
And, when harvesting your crop, remember: the funny-looking tomatoes taste just as good!
I’m Caty Weaver.