Citrus hystrix
Common Name: Thai lime 
Type: Broadleaf evergreen
Family: Rutaceae
Native Range: Southeast Asia
Zone: 10 to 12
Height: 6.00 to 25.00 feet
Spread: 5.00 to 12.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Medium
Flower: Showy, Fragrant
Leaf: Evergreen
Fruit: Showy, Edible
Other: Winter Interest, Thorns

Culture

Winter hardy to USDA Zones 10-12 where this citrus tree grows well in sandy, well-drained soils in full sun to light shade. Deep, fertile soils generally produce the best fruit crops. Best overall performance occurs in full sun in locations sheltered from strong winds. Provide consistent and regular watering. Avoid wet poorly drained soils. Trees will tolerate temperatures that occasionally drop to 32°F, but will generally not survive temperatures much below that. Plants prefer warm tropical to sub-tropical climates with abundant rainfall. North of Zone 10, this plant is best grown in containers that should be placed in sunny windows year round or taken outside in late spring but returned indoors in early fall before temperatures regularly dip below 60°F. Indoor plants should be regularly watered and foliage should be regularly misted (plants like humidity).

Noteworthy Characteristics

Citrus histrix, commonly called Thai lime or makrut lime, is a thorny, multi-stemmed, evergreen shrub or small tree of the citrus family that grows to 6-25’ tall. It is primarily native to Southeast Asia, but has widely naturalized in tropical areas with the specific location of its original distribution uncertain. Glossy, aromatic, double (two-parted), evergreen leaves from this tree are commonly shredded for use as a flavoring in a variety of Southeast Asian food dishes including soups, curries, rice, stir-fry, fish cakes, salads and marinades. Leaves may be harvested from home grown plants or purchased fresh or dried at Asian or specialty groceries. Four to five petalled white flowers are fragrant. Flowers are followed by rough bumpy green fruits (limes to 2” wide) which have a highly acidic flavor but little juice, so the juice and pulp is infrequently used in cooking. Fruit rinds are sour tasting, but often used for flavoring in a diced-up or grated form.

The genus name Citrus is from classical Latin.

Specific epithet comes from the Greek word hustrix meaning hedgehog in reference to the thorns present on this plant.

Many authorities prefer the common name of Thai lime or makrut lime to Kaffir lime because of the insulting and derogatory meaning of the word kaffir in some parts of the world (e.g., an insult used by some South African whites for blacks).

Problems

Watch for aphids, spider mites, mealybugs, and scale. Susceptible to root rot in overly moist soils.

Uses

Grown primarily as an ornamental in Florida and California. Leaves, flowers and fruit rind may be used in cooking.