Homegrown Watermelon Splitting: What Makes Watermelons Split In Garden

Split Watermelon
melon cracked
(Image credit: A. Drauglis)

Nothing beats the cool, water-filled fruits of watermelon on a hot summer day, but when your watermelon bursts on the vine before you've had a chance to harvest, this can be a little disconcerting. So what makes watermelons split in gardens and what can be done about it? Keep reading to find out.

Causes of Watermelon Splits

There are a few causes of watermelon splits. The most common cause for a bursting watermelon is erratic watering. Whether it's due to poor irrigation practices or drought followed by heavy rain, excessive accumulation of water can put the fruit under a lot of pressure. As with tomato cracking, when the plants absorb too much water too fast, the excess water goes straight to the fruits. Like most fruits, water makes up a large percentage of the fruit. When the soil becomes dry, the fruit forms a tight skin in order to prevent moisture loss. However, once a sudden surge in water returns, the skin expands. As a result, the watermelon bursts. Another possibility, in addition to water, is heat. Water pressure within the fruit can build up when it gets too hot, causing the melons to split open. One way to help alleviate splitting is by adding straw mulch, which will help retain moisture in the soil and insulate plants. Adding shade covers during excessively hot periods may help too. Finally, this may be attributed to certain cultivars as well. Some varieties of watermelon may simply be more prone to splitting than others. In fact, many thin-rind types, such as Icebox, have even been nicknamed “exploding melon” for this reason.

Nikki Tilley
Senior Editor

Nikki Tilley has been gardening for nearly three decades. The former Senior Editor and Archivist of Gardening Know How, Nikki has also authored six gardening books.