Tomatoes splitting or cracking on the vine

What you’re seeing

Concentric rings or radial cracks appear around the stem end of tomatoes as they ripen, sometimes splitting deeply enough to expose the flesh inside.

Could it be something else?

Likely causes

Ranked most common first.

1. A sudden heavy watering or rain after a dry spell. A tomato that has grown a firm skin during dry conditions takes up water fast after a soaking rain or deep watering, and the flesh swells faster than the skin can stretch.
2. Irregular watering generally. Even without a dramatic dry-then-wet swing, inconsistent watering week to week makes cracking more likely than a steady schedule does.
3. Certain varieties are simply more prone to it. Thin-skinned and some heirloom varieties crack far more readily than thick-skinned hybrids bred partly for shipping durability.

How to fix it

1. Pick cracked fruit promptly, even if not fully ripe - cracks are an open door for rot and fruit flies, and the tomato ripens fine indoors on a counter.
2. Water deeply and consistently on a regular schedule (roughly 1-2 inches per week including rain) rather than letting soil dry out between waterings.
3. Mulch around plants to buffer soil moisture swings between waterings and rain events.
4. During a stretch of dry weather followed by forecast heavy rain, give plants a moderate drink beforehand rather than letting them hit the rain already parched.

Common mistakes

• Watering heavily and infrequently. Deep watering on a steady schedule is fine; long dry gaps followed by a soaking are the problem - see watering a vegetable garden.
• Leaving ripe fruit on the vine before a forecast storm. Pick at first blush and ripen indoors.
• Skipping mulch. A layer of straw or shredded leaves smooths out moisture swings - see mulching a vegetable garden.
• Heavy pruning right before a heat wave, which exposes fruit and adds stress.

When and where it shows up

Cracking is most common in mid to late summer, especially when heavy rain follows a dry spell. Large heirloom and beefsteak tomatoes crack most, but cherry tomatoes can split badly overnight after a storm. Fruit at or near full ripeness is most at risk because the skin has stopped stretching.

Preventing it next time

Keep soil moisture even with regular deep watering and a good mulch layer, and choose crack-resistant varieties if this is a recurring problem in a climate with unpredictable rain.