Tomatoes exhibiting cracks this summer
The unusual weather this season caused tomatoes to burst at the seams, causing “growth cracks.”
Many home gardeners have been very perplexed about damage on their ripening tomatoes this summer. At the top of the tomato, there are dark cracks radiating away from the stem. It looks like a giant asterisk with the stem in the center. Or there are concentric rings surrounding the stem in the same area -- either crescents or complete circles. The cracks vary in depth from superficial to deep splits. The first thought is some new, horrible disease, but luckily, it is one of the most common problems that tomato fruit get.
Concentric rings. Photo credit: Paul Bachi, University of Kentucky Research and Education
Both problems are called “growth cracks.” They are not created by insects or diseases. They are what is termed as physiological or environmental problems. The cracks appeared because the fruit went through an extremely rapid size change. Essentially, the tomato grew so fast that it split its pants.
But why did it happen this year and not the other years that these gardeners grew tomatoes? It requires a special set of environmental events to make growth cracks a possibility. It is necessary to have a dry weather period followed by heavy rains. The months of June and July were hot and dry. At the end of July and the beginning of August, heavy rains soaked much of Michigan. The temperatures dropped and tomatoes, as well as many other plants, exploded in size. In most growing seasons, this is usually dry weather and the gardener is supplying the water regularly.
When the weather is humid at the time that the growth cracks occur, the skin damage opens the door for fruit-rotting organisms to invade. Some growth cracks develop soft, black, rotted areas. This fruit can decay rapidly.
But for most gardeners, all they have are the dark, leathery cracks. This is the tomato’s version of scar tissue. The fruit is completely usable. All that needs to be done is to trim out the damaged areas.
Growth cracks have been described as a universal malady. This year, the weather created the opportunity for growth cracks to be in many garden universes where it has never been seen before.