Choose different varieties to prevent common problem, says K-State expert
K-State horticulture expert Cynthia Domenghini says the common problem of tomatoes cracking can be solved by scheduling watering or choosing different varieties.
K-State Research and Extension news service
Home gardeners face the problem of tomato cracking, or hard cracks on the upper part of the fruit, usually spanning from or around the stem.
While the cracks do not necessarily ruin the tomato, they are unsightly, said Kansas State University horticulture expert Cynthia Domenghini.
“Tomatoes have a root system that is very dense and fibrous, and is quite efficient in picking up water,” she said. “Unfortunately, the root system can become unbalanced with the top of the plant.”
Domenghini said cracking early in the season is likely related to the top growth of the tomato, which can then result in blossom-end rot when the weather turns hot and dry. Later in the season, cracking may be caused by a sudden abundance of water after a long dry spell.
How can cracking be prevented? Domenghini suggests consistent watering and mulching. Scheduled watering will prevent a quick influx of water likely to cause cracking. Additionally, mulching will help moderate moisture levels in the soil.
Some gardeners may be already following these recommendations and doing everything right, and still end up with tomato cracking. Faculty in K-State’s Department of Horticulture evaluated different tomato varieties over several years to try and come up with the most crack-resistant tomato.
“The difference seems to be the pliability of the skin rather than thickness; the more pliable the skin, the more resistance to cracking,” Domenghini said. “The old variety Jet Star has been the most crack-resistant of any we have tested, including the newer types.”
Unfortunately, Domenghini noted, Jet Star is a variety that can put out rampant, uncontrolled growth. Of the newer, more attractive varieties, Domenghini said the Mountain Spring, Mountain Pride, Mountain Fresh, Floralina, and Sun Leaper varieties had good resistance to cracking.
Domenghini and her colleagues in K-State's Department of Horticulture and Natural Resources produce a weekly Horticulture Newsletter with tips for maintaining home landscapes and gardens. The newsletter is available to view online or can be delivered by email each week.
Interested persons can subscribe to the weekly newsletter, or submit their garden and yard-related questions, by sending email to Domenghini at [email protected], More information also is available at your local K-State Research and Extension office.