Why Do Tomatoes Split After Rain? How to Prevent Fruit Cracking

A tomato may split after rain because its interior expands faster than its skin can stretch. A dry period followed by heavy watering or rain can accelerate fruit growth, producing cracks near the stem or down the side. These cracks are called growth cracks, and they are usually a watering-and-growth problem rather than a contagious plant disease.

What causes the skin to crack?

A tomato’s flesh continues growing as it receives water. If moisture suddenly becomes abundant after a dry spell, expansion can outpace the flexibility of the outer skin. Warm, humid weather and rapid fruit development can also contribute. Some varieties, particularly large heirloom tomatoes, crack more readily than others. The University of Minnesota Extension’s tomato diagnosis guide identifies irregular watering and drought followed by rain as common triggers.

Radial cracks versus concentric cracks

• Radial cracking: splits run outward from the stem, often down the tomato’s shoulder or side.
• Concentric cracking: circular cracks develop around the stem end.
• Catfacing is different: misshapen fruit with corky scars or lobes can result from conditions affecting flower development rather than a sudden moisture swing.

How can gardeners reduce tomato cracking?

• Keep watering as consistent as possible rather than allowing severe drying followed by heavy soaking.
• Apply organic mulch to help moderate swings in soil moisture while leaving space around the stem.
• Avoid excessive nitrogen fertilizer that can encourage lush, fast growth at the expense of balanced fruit development.
• Consider crack-resistant varieties, especially where summer storms are common.
• Pick nearly ripe fruit ahead of a forecast downpour if appropriate for the variety, and allow it to finish ripening indoors.

Is a cracked tomato safe to eat?

A tomato with a fresh, superficial split may be usable if it is promptly harvested, washed, and trimmed as needed. But deep open cracks provide an entry point for microbes and rot. Discard tomatoes with mold, softness, off odors or contamination inside the fissure. Do not use damaged tomatoes for home canning; use sound, high-quality produce and a tested canning recipe. For sound tomatoes that you plan to cook, see our separate guide to peeling tomatoes with a quick blanch.

FAQ: Tomatoes splitting on the vine

Does splitting mean I watered too much? Not necessarily. A sudden change from dry to wet conditions can be more important than the total amount of water.

Do all varieties split equally? No. Fruit size, skin characteristics, growing conditions and variety all influence susceptibility.

Can you close a crack after it happens? No. Focus on promptly harvesting usable fruit and preventing similar moisture swings in later fruit.