Why Do My Watermelons Explode?

Forchlorfenuron

• Forchlorfenuron is the name of the chemical growth accelerator that some Chinese farmers used in the hope that their melons would become larger, which would then result in a larger profit at harvest time. The chemical is legal, both in China and in the United States, where American farmers often apply it to kiwis and grapevines. China Central Television studied the situation and reported that Chinese farmers were misusing or abusing legal and illegal chemicals, including pesticides and herbicides.

Damage

• Forchlorfenuron is generally safe when farmers apply it to certain crops early in their growth. However, Chinese farmers reportedly used this chemical later in the growing season. The watermelons that split open on 115 acres in China were a thin-skinned variety, which also contributed to the problem. One farmer said he counted 80 burst melons one morning, and by afternoon, 100 had split open. After two days, he “didn't bother to count anymore,” according to CBS News.

Homegrown Melons

• Home gardeners in the United States do not have access to growth enhancement chemicals such as forchlorfenuron. If you have experienced a split or burst watermelon, it could be due to overwatering, overripeness of the fruit or a combination of these two factors. Melons can “explode” after harvest when they become overripe and the temperature in your home is high enough to cause bacteria inside to grow and pressure to build.

Alternatives to Growth-Enhancing Chemicals

• Watermelons will grow plump, sweet and juicy without growth-enhancing chemicals. Natural fertilizers such as cow manure or organic compost work well, as do manure tea and fish emulsion. Alternatively, choose a commercial plant food that is low in nitrogen and high in phosphorus, such as one having an N-P-K ratio of 5-20-10. Begin fertilizing your watermelon just after the fruit begins to form by sprinkling fertilizer on either side of the row. Repeat this application in about four weeks.