Pomegranates split when their arils (the juice-filled seeds inside) expand faster than the rind can stretch to accommodate them. This usually happens after a sudden change in water availability, especially rain following a dry spell. Under the worst growing conditions, splitting can destroy up to 65% of a pomegranate crop.
How Water Triggers the Split
The most common cause is irregular watering. Pomegranate rinds become tough and less flexible during dry periods. When the tree suddenly receives a large amount of water, whether from rain, irrigation, or both, the arils inside absorb moisture and swell rapidly. The rigid rind can’t keep up, and it cracks open, sometimes dramatically.
This is the same basic mechanism behind tomatoes cracking after a rainstorm. The difference with pomegranates is that the rind is exceptionally thick and hard, which makes it strong under steady conditions but brittle when stressed. Once a crack starts, the internal pressure from the swelling arils forces it wide open.
Temperature Swings Make It Worse
Large differences between daytime and nighttime temperatures, particularly during the final weeks of ripening, accelerate splitting. High daytime heat causes the fruit to lose moisture through its surface (transpiration), tightening the rind. Cool nights then slow the tree’s water movement. When daytime temperatures spike again and the fruit rehydrates, the rind is already under tension and more likely to give way.
This is why splitting is especially common in arid and semi-arid climates with hot days and cool nights, exactly the regions where most pomegranates are grown.
Hormones Inside the Fruit Play a Role
Two plant hormones work against each other inside a developing pomegranate. One promotes growth and cell stretching, helping the rind stay flexible. The other signals maturity and slows growth, which gradually stiffens the rind. In fruits that split, researchers have found higher levels of the maturity-signaling hormone in the peel compared to fruits that stay intact. Essentially, the rind “hardens” too early or too aggressively, losing the elasticity it needs to handle late-season swelling.
Commercial growers sometimes spray a growth-promoting hormone (gibberellic acid) on young fruits to counteract this. It delays maturity slightly, keeps the rind more elastic, and maintains cell wall flexibility. Studies on several pomegranate varieties have shown that a well-timed spray in midsummer substantially reduces the cracking rate.
When Pomegranates Are Most Vulnerable
Splitting can happen at any point during ripening, but the risk peaks in the final maturation stage, typically the last few weeks before harvest. By this point, the arils are nearly full size and packed tightly inside. The rind has been hardening for months. There’s very little room for error: even a modest surge in water uptake can push the fruit past its breaking point.
Early-season cracking does occur but is less common. Younger fruits have thinner, more flexible rinds and smaller arils, so they can absorb fluctuations more easily.
Some Varieties Resist Splitting Better
Genetics matter. Researchers evaluating dozens of pomegranate cultivars in China found that varieties like Qingpidazi, Houpitian, Zhuyeqing, and Gangliu had cracking rates between 1.5% and 2.3%, making them highly resistant. Other cultivars grown in the same conditions cracked at far higher rates. The difference comes down to inherited traits: rind thickness, elasticity, the ratio of rind to aril volume, and how quickly the peel loses flexibility during ripening.
If you’re growing pomegranates at home, choosing a crack-resistant variety for your climate is the single most effective preventive step.
How to Prevent Splitting
For home gardeners and small-scale growers, the key strategies are all about consistency:
- Water regularly. Deep, consistent irrigation throughout the growing season prevents the dry-then-wet cycle that causes most splits. Don’t let the soil dry out completely between waterings, especially as fruits approach maturity.
- Mulch around the base. A thick layer of mulch helps maintain even soil moisture between waterings and buffers against sudden changes after rain.
- Harvest promptly. The longer ripe fruit stays on the tree, the greater the chance of a weather event triggering a split. Pick fruit as soon as it’s mature.
- Consider bagging. Some growers wrap individual fruits in paper or mesh bags during the last month of ripening. This reduces direct sun exposure, moderates temperature swings around the fruit, and provides a small buffer against rapid moisture changes.
Is a Split Pomegranate Safe to Eat?
It depends on how long the fruit has been open and what’s gotten inside. A freshly split pomegranate that you catch the same day on the tree is generally fine once you inspect it and discard any discolored or moldy sections. But a split that’s been exposed for days is a different story.
Open wounds on fruit invite bacteria, mold, and insects. The FDA notes that microorganisms infiltrate produce through splits and damaged sites on the rind, with water, insects, and birds all acting as carriers. Testing on fruit juice illustrates the scale of the problem: juice from intact fruit averaged about 500 colony-forming units of bacteria per milliliter, while juice from split fruit averaged 1,710,000, roughly 3,400 times more contamination.
If you find a split pomegranate on your tree, pick it immediately. Open it up, smell it, and look closely at the arils. If they’re bright, firm, and smell normal, they’re usable. If you see mold, fermentation bubbles, or off-colors, discard it. Fruit you find already split at a farmers market or grocery store should be avoided, since you have no way to know how long it’s been open.