Key Lime

Botanical Overview

  • Scientific Name: Citrus aurantifolia
  • Common Names: Key lime, Mexican lime, West Indian lime, Persian lime (though this is a hybrid)
  • Family: Rutaceae
  • Origin: Southeast Asia; widely cultivated in Mexico, the Caribbean, and the Philippines

Morphology

  • Tree Size: Small, typically 2–5 m tall; can reach 6 m in favorable conditions
  • Leaves: Small, ovate, dark green, aromatic, with pointed tips
  • Flowers: White, fragrant, five-petaled; bloom year-round in tropical climates
  • Fruits: Small, round to oval, 2–5 cm in diameter, green when unripe, turning yellow when mature
  • Seeds: Numerous, small, and oblong

Growth Requirements

  • Climate: Tropical to subtropical; sensitive to frost
  • Temperature: Ideal 20–30°C
  • Rainfall: 1000–2500 mm annually; requires well-drained soil
  • Soil: Loamy, slightly acidic to neutral (pH 5.5–6.5)
  • Sunlight: Full sun preferred for optimal fruiting

Propagation

  • Seeds: Common but slow to fruit and less uniform
  • Grafting/Budding: Preferred for uniformity, early fruiting, and disease resistance
  • Tissue Culture: Advanced method for mass propagation and disease-free planting

Fruit Development

  • Flowering: Year-round in tropical climates; peak flowering in rainy season
  • Fruit Set: 4–6 months from flowering to mature fruit
  • Harvesting: Fruits are harvested when green (for culinary use) or yellow (fully ripe)

Uses

  • Culinary: Juice, desserts, key lime pie, marinades, beverages
  • Aromatherapy & Essential Oils: Peel oil rich in limonene
  • Medicinal: Rich in Vitamin C; used for digestive and immune support
  • Agronomic Uses: Companion planting; can act as a permanent host for certain aromatic trees

Pests & Diseases

  • Pests: Citrus leafminer, aphids, scales, fruit flies
  • Diseases: Citrus canker (Xanthomonas citri), Phytophthora root rot, greening disease (HLB)

Cultural Notes

  • Often grown alongside other tropical trees for polyculture or agroforestry systems
  • Can act as a permanent host plant for inoculated aromatic trees such as agarwood (Aquilaria spp.), due to its dense canopy and tolerance of tropical soils