How to Prevent Tomato Splitting

Don't let cracks and splits ruin your tomato crop with these tips and tricks

You’ve done everything right: planted your tomatoes where they receive plenty of sun, provided rich organic soil and the right amount of fertilizer, watered plants at soil level to minimize foliar disease. Your efforts were rewarded with an abundance of blossoms followed by little green fruits. After days of patiently waiting for your tomatoes to ripen, you wander out to the garden only to discover an ugly crack marring the surface of a plump, perfectly ripe fruit. What could possibly have gone wrong?

Why Do Tomatoes Split?

The cracked skin of tomato fruits is called splitting. Even the most experienced vegetable gardener may struggle at times with tomato splitting, usually when heavy rainfall occurs near harvest time. An abundance of available water causes fruit to expand faster than the skin can stretch, resulting in cracks. Splitting can also occur due to uneven irrigation practices.

Studies suggest excess nitrogen and insufficient calcium may compound the problem of fruit splitting. Tomatoes are moderate feeders. Apply a low-nitrogen fertilizer containing calcium at regular intervals during the flowering and fruiting stages. Avoid adding too much nitrogen, which promotes foliar growth at the expense of fruiting.

Types of Damage

Cracking usually affects ripening fruit, though plump green tomatoes can also split. Impacted fruits develop one or more cracks either vertically, called radial cracking, or in rings circling the fruit, called concentric cracking. Radial splitting is most damaging because the crack exposes the flesh of the fruit, which can lead to infection by disease organisms.

Concentric splitting, as the name suggests, causes a series of cracks circling the fruits.

Though unsightly, concentric cracking typically does not expose the flesh, so disease infection is less likely to occur.

What to Do with Split Tomatoes?

Fortunately, many split fruits can be salvaged. In the case of tomatoes with concentric cracking, fruits can be allowed to ripen on the vine unless the interior flesh is exposed. Keep an eye on these fruits as they ripen to make sure they do not crack through the skin.

If the flesh of the fruit is exposed due to radial or concentric cracking, harvest the tomatoes as soon as possible. Inspect fruits for signs of disease and discard any tomatoes that have a sour smell or pus along the crack. Harvested fruit can be ripened on the counter or windowsill.

How to Prevent Tomato Splitting

Even watering is the key to preventing fruit cracks. Tomato plants use a lot of water to ripen fruits. Strive to maintain an even, steady supply of moisture and avoid sudden fluctuations. Water plants deeply a few times per week and apply a layer of organic mulch to conserve soil moisture between waterings.

Cracking is most common when heavy rainfall (or over irrigation) follows an extended dry period. If plants have experienced a dry spell and have not been irrigated regularly, reintroduce irrigation slowly. Water plants lightly at first as you slowly reestablish a regular watering routine. Likewise, watch the weather during dry spells. If heavy rain is expected after a period of drought, consider covering the planting area with a tarp support on a sturdy frame or harvesting fruit prior to the storm to avoid splitting. Harvested tomatoes can be ripened on the countertop or cooked as green tomatoes.

All types of tomatoes experience cracking, including grape and cherry types. Though some varieties are considered crack resistant, any tomato will split under extreme conditions. Careful water management is your best approach to minimizing cracks no matter what type of tomato you grow.