8b

Washington Navel orange (Citrus sinensis ‘Washington Navel’) is the most widely grown navel orange in the world, a natural mutation that appeared in Brazil in the early 19th century and was introduced to Washington in 1870, hence its name. Its tree hardiness reaches 16°F (−9°C), making it suitable for in-ground growing in USDA zones 8b and 9a. The vigorous tree commonly reaches 10 to 16 ft (3 to 5 m) in cultivation, and can reach 20 ft (6 m) in favorable ground, with a rounded habit, evergreen foliage, and fragrant white flowers in spring. Its large bright orange fruit, 7.1 to 10.6 oz (200 to 300 g), characterized by a visible secondary navel, seedless, with easy-to-peel skin, ripen in winter and offer juicy, sweet, fragrant flesh. The ultimate table orange: to be eaten fresh, as juice pressed right away (it oxidizes quickly), in salad. Graft onto Poncirus trifoliata for in-ground growing, plant against a south wall. Harvest in January-March.