The striking Hardy Orange tree - also known as Chinese Bitter Orange or Trifoliate Orange - while not a true orange, is closely related to the Citrus family. This incredibly tough plant is native to Northern China and Korea; it tolerates frost, snow and temperatures down to -20C. (It may need some additional protection in zone 5.)
First appearing in North America in the 1820s, Hardy Orange became popular with American growers as a hedgerow, or living fence; it makes an impenetrable barrier hedge with its twisted branches and long, sharp thorns. It has a tendency to be invasive in some places, so pruning is recommended.
Hardy Orange will reach a height of 8 - 20 feet. It has lovely green branches, twisted and dense with thick, 2” long thorns; trifoliate leaves; showy white, fragrant flowers; and delightful, golf ball sized fuzzy, lemon-like sour fruit that ripen slowly into Fall. Birds like to take safe refuge from predators in the fortress of branches.
The fruit - a modified berry - is very bitter, seedy and not typically eaten fresh off the tree, though it has extensive culinary uses. It is naturally high in pectin, and excellent for marmalade and other preserves; it makes a tasty lemonade; and the fruit peel can be candied or dried and powdered.
Note: Hardy Orange is very suitable for container gardening! Choose a container with a minimum 12” diameter.
Cold Hardiness: Zones 5 - 10
Edible: Yes
Size: Small Tree
Growth Rate: Slow ( 8ft after 10 years )
Nitrogen Fixer: Yes
Native Plant: No
Germination: 80-90%
Sun Requirements: Full Sun - partial shade
Soil Preference: Prefers moist, well-draining soil. Tolerant of many soil types, drought and urban pollution.
GROWING INSTRUCTIONS
SEED PRETREATMENT: Soak seeds in water for 24 hours. Mix seeds with a moistened grow medium equal to 3-4 times seed volume. Place in a plastic bag, covered tray/cells or container.
STRATIFICATION: 30 days cold/moist (5°C). Place plastic bag with seeds and soil in your refrigerator, preferably in a veggie crisper. Inspect periodically for even moisture.
POST-STRATIFICATION: Sow stratified seeds 1/4” deep. Requires soil temperatures of at least 18°C to germinate. Water evenly and regularly.
GERMINATION: When all previously mentioned requirements are fulfilled, germination generally occurs in 30-45 days.
