Why are my tomatoes cracking?
Fruit cracking is a common problem on tomatoes. Cracks usually appear at the top or stem end of the fruit. Cracks radiate out from the stem (radial cracks) or circle the fruit in concentric rings (concentric cracks). Fruit cracking is associated with wide fluctuations in soil moisture levels. A heavy rain or deep watering after a long, dry period results in rapid water uptake by the plant. The sudden uptake of water results in cracking of ripening fruit. Generally, fruit cracking is most common on the large, beefsteak-type tomatoes.
Fruit cracking can be prevented by supplying the tomato plants with a consistent supply of moisture during the summer months. During dry periods, a thorough soaking once every 7 days should be adequate for most tomato plants. Conserve soil moisture by mulching the area around tomato plants with dried grass clippings, straw, shredded leaves, or other materials. Also, plant tomato varieties that possess good crack resistance. Tomato varieties that possess good to excellent crack resistance include ‘Jetstar,’ ‘Mountain Spring,’ and ‘Mountain Fresh.’