Blood oranges are mid-season fruits, meaning they are ready to pick and eat in the months of January and February. Blood oranges originated in southern Asia, but have migrated and been shipped to various locations, from Australia to the United States. The trees do well in warm, sunny climates and will not withstand severe winters and heavy frost. Healthy trees yield fruit, but their exact ripening times are often dependent upon the growing conditions within the tree's planting region.
Texas A&M horticulturists state that oranges do not ripen so much as mature into an optimum eating state. When left unharvested oranges soften and drop from trees in inedible heaps. It is best to pick fruit before they soften and drop. Home growers can examine the fruit's stem. When the stem is drying out the fruit is ready to drop from the tree. Picking the fruit when the stem starts to dry is one way to ensure the fruit does not soften and drop. In Southern California and Texas a grower can start picking fruit in January while the stem is still green, but the fruit itself will often hold onto the tree until March, after which time the fruit becomes over-mature.
Blood Orange Varieties
Growers in Southern California have successfully planted the following mid-season blood orange varieties: Moro, Sanguinelli, and Tarocco as well as the light red-fleshed Cara Cara. Texas growers consider Sanguinelli to be a late-season variety and ready for harvest in late February and early March. Overall, Texas growers do not recommend blood orange varieties be grown in their state, as the fruit tends to be inferior to that of other sweet oranges. Florida growers also plant Ruby varieties, which are seeded and have flecked red flesh rather than an exuberant blood color. Florida growers also designate Ruby as a dual-purpose tree -- providing both fruit and ornamental interest.
Newly planted orange trees should be encouraged to grow rather than fruit in their first few growing seasons. To encourage growth, growers cut back any fruit or flowers the tree produces during its first two fruiting seasons. Harvest fruit from a new tree in the third growing season, when the tree's root system and size have been better established. Following this method allows for a greater harvest yield. Growers from the University of Florida Extension recommend cutting back any sprouts or shoots emanating from the trunk or base of the tree, as these limbs will misdirect the tree's energy and interfere with maximum fruit production. Make cuts flush with the tree's body. This eliminates the possibility of fungus or pests making a home on stubs.
Even when fruit is harvested at the optimum time the fruit may be less than adequate. Seedy, tart and dry fruit is the result of a harsh winter, one where the fruit has frozen, thawed and frozen again. To prevent this kind of damage, ensure that your region can sustain nighttime temperatures above 30 F. If not, then choose a hardier citrus variety such as tangerine or use your orange trees for ornamental purposes only.