Why a Tomato Cracks and What to Do About It

Tomato cracks (sometimes called “growth cracks”) are a problem associated with growing conditions. Dry weather that gives way to excessive watering or a rainy period can lead to cracking.

Here’s what happens when a tomato cracks:

• Tomato plants get too much water too fast.
• A tomato’s interior grows quickly as it absorbs the extra water from rain or disproportionate watering, but it expands too fast.
• The tomato skin can’t stretch to accommodate the extra fluid.
• Cracking alleviates pressure.

What do tomato cracks look like?

Radial cracks
Photo: Colorado State University

Concentric cracks
Photo: Colorado State University

Cracks usually affect the stem end of the tomato (the entry point of water into the fruit). There are two types of cracks:concentric and radial.

Concentric cracks: circles that span a section or the entire circumference of the tomato around the stem end of the fruit
Radial cracks: straight lines that extend outward and downward from the stem node

When do tomato affect fruit?

• during warm, wet weather
• during wet weather that follows a dry period
• after excessive watering that follows a dry period

Can I eat cracked tomatoes?

Yes. Pick a cracked tomato as soon as possible to avoid infection. When preparing a cracked tomato, simply cut out affected parts. Cracked tomatoes don’t keep as long as unaffected ones.

 

How do you prevent cracks?

• Plant crack-resistant tomato varieties that have elastic skin, including Daybreak, Early Girl, Earl of Edgecombe, Heinz 1350, Jet Star, Juliet, Mountain Delight, Mountain Pride, and Valley Girl.

• Mulch plants (wait until they’re established – about 3-5 weeks after planting) to help retain moisture in the soil.
• Keep water supply even throughout the season. While you can’t control the weather conditions, you can make sure that plants are on a regular watering schedule. Tomato plants need 1-3” water a week (including rain.) During dry spells, water tomatoes deeply so that subsequent rain won’t shock skins and lead to unnecessary cracking – use a drip hose or other irrigation system. Ask a neighbor or friend to water your tomatoes while you’re on vacation.
• Apply balanced fertilizer. When blossoms and fruit develop, tomatoes need more phosphorus and potassium. Excessive nitrogen can cause plants to grow too quickly, leading to cracking.
• Don’t over-fertilize. Excess nutrients can cause a growth spurt. Tomatoes can have a hard time compensating and may crack.

Special tips

• Beefsteak varieties are more prone to cracking.
• If tomato plants dry out, water them just enough to keep them alive. Too much water at one time sets up conditions for tomato cracking. Once your plants have recovered from their dry spell, slowly re-establish a regular watering schedule.