Your orange tree (Citrus sinensis), heavy with fruits, may seem ready for a huge harvest, but most varieties are not set for picking until 7 to 15 months after successful pollination. Unlike apples and avocadoes, oranges do not ripen when picked off of the tree -- they need a long period of warm days to sweeten the internal juices. However, there are several strategies to determine ripeness before pulling fruits from the tree.
Time of Year
Among the numerous orange varieties available in U.S. Department of Agriculture plant hardiness zones 9 through 11, each one has a particular ripeness window, based on the time of year. In general, oranges are ready for picking between September and May. Early-season types, like "Hamlin," need to be picked in October at the latest. In contrast, late-season varieties need until February to achieve full sweetness, such as "Valencia." Midseason types are commonly ready by the end of December, like "Jaffa" cultivars. These particular ripening times are contingent upon proper soil management and overall tree care to produce healthy fruits on time.
Determining ripeness from peel color is often difficult because oranges physically respond to cold and warmth through greening. For example, warm air and soil causes the peel to have a greenish tinge, while oncoming winter cold stimulates an orange color. In general, a ripe orange has one quarter of its peel showcasing a consistent yellow to orange hue. You must observe your fruits and make an educated decision based on consistent color and the variety's typical harvest time to determine the right picking time.
Without pulling the fruits from the tree, you can determine ripeness from texture as well. By placing your hand under the fruit, slightly lift it to feel the weight. A ripe orange feels heavy with juice while the peel maintains an unyielding strength when you squeeze it. Any emerging soft spots indicate that the fruit is almost too ripe, or overmature. Your goal is to pick the fruits prior to any softening so that they are perfect for snacking or juicing.
Once your orange tree reaches maturity with prolific fruiting, using a simple taste test helps you determine ripeness. Avoid tasting any tempting fruits in June or July -- they will be incredibly sour from lack of sugars. Choose to taste-test in the late fall or early winter. By clipping the fruit from the tree, rather than pulling it, you preserve the peel's integrity. Any damage to the peel allows pathogens to infiltrate the juicy interior. A sweet taste tells you it is time for harvesting. If you find an unripe orange, allow the rest of the tree to ripen more in the sunlight -- you will have more oranges than you know what to do with when they are fully ripe.
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