March has some claws. Lovely sunny days snarl and turn into ice storms like an ill-tempered housecat shreds a friendly hand. The hardy orange (Poncirus trifoliata) has some of the same qualities. This Asian fruit tree is a four-season beauty, with fragrant white flowers in spring, glossy dark green leaves in summer, and small green fruits that turn yellow-orange in fall and persist into winter. But there are claws—literally. Vicious 1- to 2-inch green thorns cover the branches, making this a tree for the wary and the well-protected. Plant a single specimen—or an impenetrable hedge—on the far side of the yard, where you and your purring kitty can view it from the picture window.
Common name: Hardy orange, bitter orange, Japanese bitter orange
Botanical name: Poncirus trifoliata
Plant type: Deciduous shrub or tree
Zones: 6 to 9 (Zone 5 with protection)
Height: 8 to 20 feet
Family: Rutaceae
Growing conditions
• Sun: Full sun
• Soil: Average
• Moisture: Medium
Care
• Mulch: Mulch to preserve moisture in the soil, but leave a few inches of space around the trunk.
• Pruning: Can prune to a tree shape by removing lower branches. Remove diseased, damaged, or crossing branches.
• Fertilizer: Not needed.
Propagation
• By seed or cutting.
Garden notes
• The hardy orange’s 1- to 2-inch fruits are edible, but too sour and seedy for eating out of hand. Use them to make marmalade or lemonade, or leave them on the thorny branches for winter color.
• The glossy, three-lobed (trifoliate) leaves turn yellow in the fall.
• Hardy orange bushes grown close together make a truly intimidating hedge that will keep almost everything with skin on one side or the other. They also provide great shelter for birds.
• Put hardy orange in a spot where it can be admired by all but not bumped into by pets, children, or inattentive adults.
• Hardy orange is reportedly invasive in some areas, so check with your local extension service (or at http://plants.usda.gov). If you’re in doubt (especially if you live near a wilderness area), gather the fruit before it ripens.
Cultivars
• ‘Flying Dragon’ has twisted thorns and grows 6 feet tall.
All in the family
• Poncirus trifoliata is the only species in its genus. It is used as a rootstock for some commercially grown citrus fruits.
• Rutaceae is known as the citrus family; within it is the genus Citrus. Oranges, lemons, limes, and grapefruit are all in this genus.
Where to buy
• Plant and Gnome, Charleston, WV, 304-345-1282, www.plantandgnome.com
• Companion Plants, Athens, OH, 740-592-4643, www.companionplants.com
• Lazy S’s Farm Nursery, Barboursville, VA, www.lazyssfarm.com
(Text by Elizabeth Noll, photo of Poncirus trifoliata by Tracy Walsh)