Botanical Name: Citrus hystrix
You can count on kaffir lime tree to add color and fragrance to your home. This dwarf lime tree is fun to grow, and its needs are few: give it direct sunlight, frequent watering -- and if the air is dry, you'll want to mist with tepid water a few times a day.
Kaffir lime is also known as kieffer lime, Thai lime, makrut and wild lime in its native Southeast Asia habitat. Whatever you call it, this indoor fruit tree is a delight to grow for its citrusy fragrance and unusual appearance.
The woody stems of kaffir lime are densely covered with double, glossy green leaves. Kaffir lime leaves are highly aromatic and a key ingredient in many Thai recipes. You'll also find sharp thorns along the stems, so watch for them when handling this plant.
With good care, you can expect your kaffir lime tree to be loaded with small, pinkish-white flowers, followed by fruit that turns from light to deep green as it matures. Kaffir limes have a bumpy texture, and they're small -- only growing to about 2 in (5 cm) in diameter.
Fruit trees won't bloom and produce fruit if they don't get enough strong sunlight. If you don't have a sunny window, use a full-spectrum fluorescent grow light.
Let the sun shine in. Indoor citrus trees need as much light as you can give them. Place your lime tree directly in front of a window where it will get several hours of direct sun each day. Move it outdoors for the summer, if you want. Make the move a gradual one, exposing the plant to a little more sun each week. Be sure to bring it back in before the first frost.
Pollinate your plant. A kaffir lime tree that is grown indoors will need to be hand-pollinated to trigger fruit production. Here's how: Use a small, dry paintbrush to dab each flower. Wiggle the brush around the center of each flower, moving from flower to flower. This carries the pollen from male to female flowers, just like bees do it.
Prune branches. Prune your citrus tree back when new growth starts in spring. Pruning citrus trees' long branches will encourage new branches to emerge from just below the cut. Cut at a 45° angle just above a leaf node (where a leaf stem attaches to a branch). Watch out for the thorns when pruning.
This evergreen perennial shrub won't go dormant in the winter, so continue to give it warmth, light and moisture year-round. With good care, it'll be loaded with limes every year.
Origin: Southeast Asia
Height: Up to 5 ft (1.5 m) indoors; prune it back to control its height
Light: At least 8 hours of direct sun each day. Turn the plant a quarter turn every week to give all sides equal light for good growth. Indoor fruit trees grow well with artificial lighting, too.
Water: Water thoroughly and empty drainage tray. Aim to keep the soil evenly moist, but not soggy.
Humidity: Moderate humidity. Put the container on a tray of wet pebbles and mist the foliage to increase humidity.
Temperature: Average to warm room temperatures 60-85°F/16-29°C. Hardy to USDA Zones 9-10, kaffir limes will tolerate warmer temperatures, but not frost.
Soil: Peat moss-based potting mix.
Fertilizer: Feed every 2 weeks in spring and summer with this organic fruit tree fertilizer. It contains all the nutrients fruit trees need for healthy root growth and promotes flowers and fruits.
Propagation: Take stem cuttings in early summer. With a sharp knife or razor blade, take 4 in (10 cm) stem tip cuttings with at least 2-3 leaf nodes without flowers or fruit. Dip cut end in rooting powder before inserting in moist potting mix, then enclose in a plastic bag to maintain humidity. Stem cuttings will root in about 6-8 weeks.
You'll get more flowers if you put your plant outside for the summer and fall.
A few months of hot, sunny days followed by cool fall weather will help promote flowering.
Buy from a reputable grower to ensure the best quality. You'll find kaffir lime trees for sale at some online nurseries.
Kaffir limes are in the Rutaceae family, along with key limes, oranges, lemons and grapefruits.