The Kaffir lime tree is a dwarf citrus tree that is usually cultivated for use in Asian cooking. Because the Kaffir lime only reaches a height of 1.5 metres (5 feet), the tree is ideal for container gardening and can be grown indoors.
Carefully look at the available sources for your lime tree. It is possible to grow Kaffir limes from seed, but this method is not recommended because it can be unreliable. Kaffir lime trees are readily available from tree nurseries. If you order from an online source, make sure that you choose a tree from a reputable dealer. Find out how the tree is delivered and whether the merchant will guarantee the tree and under what conditions. Get a one-year-old tree because it will produce blooms and fruit faster.
Buy a large pot with good drainage, preferably one made of plastic or foam that retains moisture.
Place a layer of stones in the pot and then add a well-draining soil. Use a good quality potting soil, one that includes 25 per cent compost.
Add about 125 ml (1/2 cup) of slow release fertiliser and mix it into the soil.
Bury the roots of the tree completely and water it.
Understand that Kaffir limes need plenty of light, water and humidity as they are growing. Choose a large enough space for the tree close to a sunny window where it can get plenty of light. The tree should be protected from heating and cooling vents but still have good air circulation.
Check the moisture of the soil frequently. Too much water may result in root rot while too little will keep the tree from thriving. It is best to water thoroughly and then let the soil dry out a bit before watering again. Mist the tree regularly with a spray bottle of water to provide the tree with the humidity it needs.
Take steps to make sure that most of the flowers produce fruit. Spring is the time when the lime flowers the most. But when you grow plants indoors, bees and other insects cannot get inside to pollinate them. To ensure fruit production when plants are growing indoors, use a small brush to lift the pollen from the stamen of one blossom and gently dust it onto the pistil in the centre of another. Within a few days the pistol should begin to develop a tiny new fruit.
To prevent acid and pest problems, every two months dissolve 2 ml (1/2 tsp) of magnesium sulphate, also called Epsom salts, into 1 litre (1 quart) of room temperature water and add it to the soil.
Kaffir limes require acidic soil -- if the leaves begin to turn yellow, the soil does not have enough acid in it.
Although Kaffir limes do not usually have many pest problems, the tree must be kept away from any other plants that might be infected by mites or scale.
Kaffir limes and leaves are mainly used for cooking. To encourage growth, pick the leaves every few weeks. Use them fresh or dried in Asian cooking. To retain their freshness the leaves and the fruit can also be frozen in freezer bags and used as needed.
For other household uses, crush the leaves to release their fragrant oils and use in potpourri, add to rinse water to scent and condition hair, or use the oils in other household cleaning.
Kaffir lime trees are very thorny and must be handled carefully to avoid injury.