Why Does Watermelon Split While Growing?

Heavy Rain

• This is the main culprit for split watermelons. An almost-mature watermelon is more than 90 percent water, according to Clemson Cooperative Extension. A heavy rainfall causes the roots to take up as much water as possible, sending it to the leaves and fruit. Unfortunately, the melon takes up too much water, bursting the fruit.

Inconsistent Watering

• Although the fruit is full of water, the plant itself does not need heavy watering. The roots go deep into the soil and take in water well below the surface. A deep, weekly watering during the driest part of the season suffices. If you forget to water during a dry spell, don't dump gallons of water onto your plant. This causes the roots to take in more water than the plant can handle and bursts the melon. Provide small amounts of water, less than ½ gallon, for a few days until the plant appears revived.

Watering Too Often

• Giving a melon plant frequent, shallow waterings keeps the plant from developing its deep roots. Shallow roots cannot take advantage of water far below the soil's surface, and the plant suffers if not watered. A properly rooted melon only needs watered weekly during dry spells. A melon plant with shallow roots dries out easily, and even moderate rainfalls cause it to take in too much water, splitting the melon.

Preventing the Split

• Proper watering is most important. Watering deeply during the driest times encourages deep root growth. If a rainstorm is expected, pick the melons that are almost ripe. They can be stored inside for several weeks until ready for eating. A slightly less ripe melon is better than one that has split open.