Citrus Fruit Split

Your lovely citrus trees have gone from blossom to green fruit to nearly done when - oh, no! - a significant number of fruits crack and split open just before they are ripe enough to eat.

Citrus fruit split

​It is frustrating to the home gardener to have put so much effort into caring for fruit trees only to lose most or all of a crop, but this problem is preventable.

Citrus fruit split is not a disease. Instead, it is a watering issue. Citrus fruit split commonly occurs from September through November. The exact cause is still not yet fully understood. Botanists believe that citrus splitting is related to extreme fluctuations in humidity, soil moisture, temperature, and fertilizer levels. Fruit split can also occur in tomatoes and pomegranates.

When a citrus tree becomes drought-stressed, it will pull moisture from its fruit to maintain its other functions. The leaves will appear cupped. If the tree is irrigated heavily at this point to “make up” for the water that wasn’t available earlier, the fruits will swell so fast that their skins crack. These cracks begin at the navel, or stylar, end, where the rind is weakest. Navel oranges are the most likely to develop citrus fruit split.

​Rather than compounding the problem of insufficient water during hot, windy weather, water the tree lightly for a few days, slowly building up the moisture levels. The same holds for fertilizer. If your citrus trees regularly experience summer drought, rather than feeding large amounts in April, June, and August, fertilize lightly during the growing season, February through May.

While split oranges are technically edible, most are not ripe enough to taste good. Since these fruits are susceptible to diseases, such as Alternaria rot, insects, and other pests, it is a good idea to discard these fruit or put them in the bottom of your compost pile.