Splitting of navel oranges and other citrus fruit occurs because of a variety of cultural and environmental factors but fortunately affects only a small percentage of fruit on a given tree. (Photo by Ottillia “Toots” Bier)

Q: I’ve noticed that some of the navel oranges on our tree have rind that is splitting vertically from the navel to the stem.  Why?

A: It’s disappointing to see your long-awaited crop of navel oranges begin to split as the harvest season approaches.  Even commercial growers can experience this frustrating situation, and it can occur on other types of citrus too, not just navel oranges. The good news is that this is not the fault of a disease or insect.  Instead, fruit split in citrus is believed to be caused by cultural and environmental conditions.

Culturally, it’s important to maintain an even water status in the soil. Never allow your tree to become droughted before applying water. When a citrus tree becomes droughted, it responds by pulling water from the fruits in order to spare the leaves. Then, when water is applied, the tree moves water and nutrients back to the fruits, but it may be more than the fruit is capable of holding, making a split likely. In navel oranges, the navel is the weak point of the fruit so the split is most likely to begin there. Applying fertilizer in small amounts on a monthly schedule from late winter through early summer, instead of in one or two big doses, may also help to maintain an even rate of growth.

Environmental conditions will also contribute to fruit splitting. We have had some especially hot and windy conditions periodically this summer and into fall, and it is likely that this is what happened to your tree. Sunburn and windburn can toughen the rind of the fruit, making it difficult, if not impossible, for the fruit to expand as it tries to grow. If generous amounts of water and fertilizer are applied sporadically, the fruit will likely split. Obviously, you cannot control the weather, but if hot, windy weather is expected, it may help to irrigate the day before to try to minimize your tree from experiencing drought conditions.

Fruit on young trees is especially susceptible to wind and sun damage, but as the trees develop a nice full canopy of leaves, the fruit becomes more protected. Fortunately, fruit-splitting rarely affects more than a small percentage of the fruit on a tree, so as young trees get larger and more productive, the small losses to splitting are not so disappointing. Hopefully, the weather will be less challenging to our gardens next year.

Q: We have a very nice and very large pomegranate bush that needs to be pruned back quite a bit to make room for some construction. We plan to cut it back as soon as we harvest this fall’s crop. Will a severe pruning prevent us from getting fruit next year?

A: Pomegranate produces its flowers and subsequent fruit on the current year’s growth. If you prune this fall or winter, the new growth that it makes in the spring will produce the flowers and fruit crop you desire, although the crop will be smaller since the plant itself is smaller.

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