The key lime is sometimes called the Mexican lime or the West Indian lime. These small limes are about an inch in diameter, but can sometimes be slightly larger or smaller. When ripe, key limes are an intensely flavorful sour lime suitable for cooking and use in sweetened drinks and dishes. Key limes can grow either in the ground in suitable climates or in containers.
The Key lime is native to the Indo-Malayan region. It was likely brought to the Iberian Peninsula during the Crusades and was likely spread to North Africa through traders and Arabs taken by crusaders. It was likely introduced into the Americas by Spanish Conquistadors. By 1520, Key lime was commonly grown in Haiti. By 1839, the cultivation of key lime in Florida was already established and reported as "increasing." The exact date of its introduction to Florida isn't known.
Height and Appearance
Key lime trees grow to between 6 and 13 feet. They have numerous slim branches. The leaves of this evergreen tree are aromatic and oblong. The 2- to 3-inch-long leaves are leathery and round at the base. They range in color from purple to deep, olive green. Two-inch flowers eventually turn into the small Key lime fruit.
Climate and Range
Key limes are more sensitive to cold than lemons. They do best in warm, moist climates that get between 80 and 150 inches of rain per year. However, it can be tolerant of drought and can be susceptible to fungal diseases during periods that are unusually wet. Key limes are suggested for growing in USDA hardiness zones 9 through 11.
Soil and Water
Key lime is very tolerant of different soil conditions. However, it responds well to the periodic addition of lime to raise soil pH. Without adding lime, crops yields can be lower and the fruit can have a thicker skin than with higher pH soils. The only soil that doesn't suit the key lime is thick, heavy clay. Even though this lime is drought-tolerant, watering and irrigating during unexpected dry periods can help maintain the quality of your fruit.
Other than the standard Key lime, a few varieties have been grown over the years. The Everglade is a cross between a Key lime and a grapefruit or pomello. The Kagzi is the name given to the Key lime varieties cultivated in India. The Palmetto is a Key lime that has been pollinated with a Sicilian lemon. Another well-known variant is the Yung. Although the exact origin isn't known, it was introduced by George Yung into California in the late 19th century.