Many trees with citrus fruit have thorns, but other thorny trees and shrubs bear fruit, too. Plants produce thorns to defend themselves from predators and can sometimes keep unwanted guests out of your yard. Unfortunately, thorns can scratch the skin, making them unwelcome plants for children’s play areas.
Well-Known Citrus Trees
Certain types of thorny citrus trees produce well-known and delicious fruit. Mandarin orange “Clementine” trees (Citrus reticulata) produce small, sweet, seedless, easy-to-peel oranges from fall to spring. Key lime (Citrus aurantifolia) bears fruit in winter, spring or summer, and its notable flavor is a favorite for making key lime pie. Both citrus varieties are evergreen, grow in U.S. Department of Agriculture plant hardiness zones 9 through 11 and beget fragrant, white blossoms. They require full sun and moist soil for best fruit production.
Unusual citrus varieties add interest to your landscape. The uniquely shaped fruit on Buddha’s hand (Citrus medica) begins to ripen starting in late fall and, as it grows, divides into finger-like projections. Suited to USDA zones 10 through 11, the fruit is valued for its lemon-flavor skin. Hardy orange (Poncirus trifoliate) is a relative of citrus (Citrus spp.) you can grow in USDA zones 5 through 9 and is considered invasive in some areas. Its small, green, lemony-tasting fruit ripens to yellow in the fall and the rind makes good marmalade. Both of these thorny evergreens require full sun and offer fragrant, white flowers.
Native to Eastern North America
Some trees native to eastern North America have thorns and produce fruit. The long pods on honey locust (Gleditsia triacanthos) ripen in late summer, persist into winter and have sweet, edible pulp -- but don’t eat the seeds. It grows in USDA zones 3 to 8 and commercial varieties are typically thornless. The fruit on cockspur thorn (Crataegus crus-galli) ripens in September to October and, although edible, is typically left on the tree to feed the birds. It has showy, but unpleasantly scented, flowers in spring and offers scarlet-red leaves in autumn in USDA zones 3 to 7.
Sea buckthorn (Hippophae rhamnoides) and “Hinnonmäki Röd” gooseberry (Ribes uva-crispa) are thorny shrubs that turn out edible berries. The orange berries on sea buckthorn ripen in the fall and are featured in a type of orange juice commercially made in Russia and Germany. This plant grows in USDA zones 3 through 8 and its fruit is also used in tea and jams. Hinnonmäki Röd is just the right choice if you want a gooseberry bush with loads of sweet-tasting fruit with tart skin that ripen in July. This vigorous shrub grows in USDA zones 4 through 6 and is illegal to plant in some areas of the Northeast and Northwest because some varieties act as a host for the disease white pine blister rust.