Kaffir lime trees (Citrus hystrix) also are known as kieffer lime, caffre lime, porcupine orange and leech-lime. They are fruit-producing trees indigenous to Indonesia, Thailand and Malaysia and are hardy in the USDA Zones 9 to 10. The Kaffir lime is recognised by its lumpy exterior and relatively small-sized fruit, which reaches about one and a half inches in diameter. Kaffir lime trees will grow between eight and 10 feet if grown in containers and approximately 15 to 20 feet if grown in the ground.
Extract the Kaffir lime seeds from the pulp. Wash them by placing them in a strainer and running tepid water over them for approximately one to two minutes.
Mix together equal parts of peat moss, loam and sand in a large container, like a metal bowl or plastic bucket. Put the growing media into individual three or four-inch plastic pots until they are filled.
Pack down the growing media until it's firm and well compressed in each of the three or four-inch pots. Place the pots into a watering tray, or any other container that can hold about one inch of water.
Pour water into the tray so the three or four-inch pots will absorb enough water to become well saturated. Drain out any remaining water after the pots have been moistened.
Poke one-half deep holes in the centre of each three or four-inch plastic pot. Drop into each hole, two to three of the Kaffir lime tree seeds. Then, sprinkle approximately one half inch of the growing media over the top of each of the holes.
Transfer the tray of pots into a warm, bright location. The location should have a consistent temperature of between 21.1 and 23.9 degrees Celsius at all times. Ideally, eight to 10 hours of light daily also should be available. Germination of Kaffir lime tree seeds can begin in as little as seven days, but can take up to two weeks. Pot up the Kaffir lime tree seedlings into larger containers when they're about two to three inches tall.
Fill up a growing container like a small wooden planter, or barrel with a good quality growing media until it's about one-half to two-thirds full.
Pour water into the container to thoroughly saturate the growing media.
Remove the Kaffir lime tree from its growing container by turning the pot upside down and gently tapping the rim of the pot on a sturdy object, like a fence post, or you can use the base of your hand.
Set the Kaffir lime tree seedling into the new growing container. Make sure it's sitting in the centre of the pot, level and straight.
Scoop in potting mix into the container to fill it full with soil. Pack the soil down around the Kaffir lime tree and then water the tree thoroughly.
Fertilise the Kaffir lime trees monthly using a granular fertiliser that is made for citrus trees, such as 8-3-9 or 8-2-10. Make sure you follow the directions so you will apply the correct amount of fertiliser per your size tree.