Tomato fruit cracking

Tomatoes can crack in two different ways, as a horizontal circle, concentric cracking, or as a straight line split from the stem end to the bottom of the fruit, called radial cracking. Some varieties are more likely to crack than others, but all tomatoes will crack when overly ripe. Other contributing factors to cracked tomatoes include fluctuating moisture or temperature levels which cause uneven growth.

Temperature
Large fluctuations in air temperature can lead to a start-stop growing process, and the tomatoes experience periods of rapid growth after a sudden temperature increase. This type of cracking usually results in a scar or brown, roughened surface. Do not transplant your tomatoes outdoors until the temperature has steadied. In temperatures above 85 degrees Fahrenheit, tomatoes are more prone to cracking. Do not over-prune your plants as the leaves will provide necessary shade for your fruits.

Water
Irregular moisture will also lead to cracked fruit. Low moisture levels cause slower fruit growth, and an increase in moisture, causes the inside of the fruit to grow more quickly than the skin can manage, resulting in a crack or split. Maintaining even moisture levels is the way to prevent for this type of cracking, which is characterized by deep scars and splits. Tomatoes require 2 inches of water per week, either by rainfall or irrigation.

Mulching
To help maintain even soil moisture, mulch your tomato plants after transplant. Placing a 2 inch layer of mulch around the base of your plants will provide a steady supply of extra nutrients to the plants for the duration of the growing season as well as helping maintain steadier soil moisture levels. Mulch will also reduce of weed growth, leaving more water and soil nutrients for your tomato plants.

Growing Area
While you cannot control outdoor air temperatures, planting your tomatoes in an area that receives a minimum of 6 hours of full sunlight each day will ensure adequate light and a steady supply of warmth in case of fluctuating temperatures. Planting your tomatoes in well-draining soil or in raised garden beds will help prevent water-logged soils. If you do not have a space with suitable growing conditions, consider a container garden. Container tomato plants can be moved to ensure steady sunlight and to protect them from inclement weather, and the soil moisture levels can also be kept steadier.

Why a tomato plant cracks and what to do about it?

Tomato 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?

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

Concentric cracks

Radial cracks

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.