Kaffir lime, the small, bumpy citrus that lends its tang to Asian cooking

Kaffir limes growing on a citrus hydrix tree

Looking for originality in your garden AND your cooking? Kaffir lime is the tree you need to grow! Discover how to plant and care for it, and you’ll be overloaded with fruits that look like a green lime with a hundred bee stings.

Kaffir lime key facts :

Botanical nameCitrus hystrix
Family – Rutaceae (Rue family)
Type – fruit tree

Height – 8 to 20 feet (2.50 to 6 m)
Breadth – 6 to 10 feet (2 to 3 meters)
Exposure – sun
Soil – should contain lots of organic material, not limestone, well-draining
Hardiness – not so hardy 23°F (-5°C)

foliage: Evergreen
Flowering
: spring
Harvest: Fall

Table of Contents: :

Kaffir lime, an introduction

In many respects, kaffir lime looks a lot like yuzu:

  • a round but waffled fruit, quite similar to lemon;
  • stems that have no thorns;
  • oval foliage, deep green and leathery, as is typical of citrus tree.

This fruit tree is native to Asia, more specifically an Indonesian island located east of Bali called Sumbawa.

Planting kaffir lime

The tropical climate of kaffir lime’s region of origin makes growing it a bit difficult: you can’t plant it just anywhere. To grow, it indeed needs a specific environment:

  • sun-filled space to produce nice fruits;
  • rich and fertile soil;
  • soil with a neutral pH, both moist and well-drained.

When and how to plant makrut lime?

Makrut (another name for kaffir lime) isn’t very hardy, so it’s better to plant it in spring. However, if you live in regions where winter is mild, you can also do the planting in fall.

Makrut can only be planted directly in the ground in areas with a tropical climate, or in places where it never freezes over in winter. Worry not! The growth pattern of this fruit tree make it possible to plant it in pots in order to bring it indoors before the first frost hits.

If your location checks all the kaffir lime requirements, most of the work is done already, and you’ve simply got to:

  • dig a planting trench that’s 8 inches (20 cm) wide and deep.
  • feel free to amend the soil with soil mix or ripe compost.
  • If the soil feels “heavy” (clayish), also add some sand or even wood ash to lighten it up.
  • Work along the bottom of the hole with a spading fork or a broadfork, this helps mix all your amendments together.
  • Pull your makrut lime from its pot and tease a few roots from the root ball, without breaking them.
  • Settle the tree in the hole, and backfill it, pressing the soil down as you go. Towards the end, as you’re putting soil back, form a watering bowl to retain water.
  • Water abundantly.

Makrut lime in a pot:

Pots and containers works well for kaffir limeThe most important for growing kaffir lime in a pot is the container: it must be large enough and also have a drainage hole at the bottom to let water drain away.

As for the potting soil, mix the following: ¼ peat soil, ¼ sand, and ½ soil mix. These ingredients are used in garden stores to prepare citrus potting mix.

Also, you can add perlite (sometimes sold under the name “vermiculite”). This last additive enhances drainage while increasing water availability in the substrate.

Before the planting itself, spread a drainage layer of clay pebbles an inch or so thick (a few centimeters) along the bottom, without clogging the holes. Fill the rest of your container with the potting soil, and settle your makrut lime inside. Around the root ball, add more soil and press it down. The last step is to water once, abundantly.

Smart tip: To keep moisture in the ground, spread natural mulch to reduce water loss through evaporation.

Caring for kaffir lime, makrut lime

Kaffir lime needs particular care in the following:

  • In spring and summer, make sure you’re on top of the watering so that the soil stays moist without staying drenched. During the dormant phase (fall, winter), reduce the amount of water you’re providing.
  • In case of heavy freezing, protect trees growing outdoors with winterizing fleece.
  • Planting guide for kaffir limeAdd special citrus fertilizer twice a year:
    • at the beginning of spring, with a fertilizer that contains more phosphorus (P) to increase blooming (and thus fruit set).
    • in fall, better to give your makrut lime tree a fertilizer with a higher potassium content (K), it’ll boost its health before winter.
  • For potted makrut lime, schedule a repotting every 4 to 5 years, to renew the substrate and slightly increase the size of the container.
  • Add fresh mulch every year.

Note that pruning isn’t necessary, except to remove dead or damaged branches. Do so at the end of fall.

Propagation:

To obtain new makrut lime specimens, either sow its seeds, or prepare softwood cuttings at the end of summer.

Diseases and pests:

Trap to catch kaffir lime pestsMakrut lime is especially vulnerable to parasite insects such as:

Even though it isn’t a disease, but a nutrient deficiency, kaffir lime occasionally suffers from chlorosis.

Harvest and keeping

Harvest of a few kaffir limesMakrut lime fruits ripen around the middle of fall (October, November).

Pick them when they’ve turned a beautiful, deep green color: that’s when they’re most fragrant and tasty.

Leaves are ready for harvest from mid-spring to the end of summer. Don’t remove too many, it would weaken the tree.

Keep the fruits either in the vegetable compartment of the refrigerator (for a fortnight) or in the freezer (for several months). Same thing for leaves.

Cooking with Kaffir lime

Makrut is interesting in cooking both for its fruits and for its leaves.

Fruits

Makrut lime only gives very little juice, so what’s mostly used in cooking is its very fragrant peel. Shred a slivers off with a grating tool. It’s ideal to complement gravy, desserts, and even to flavor rhum.

Leaves

Cooking a fish with kaffir limePick them at the latest possible moment to ensure they’re as fresh as can be: their taste is enhanced proportionally.

Slice them into thin slivers and toss a few in your recipes, gravy, or prepare an infusion with them.

They’ll add light citrus-y taste to all your culinary achievements.


Image credits (edits Gaspard Lorthiois):
Pixabay: Hartono Subagio, Najib Zamri, an anonymous photographer
CC BY 2.0: Maja Dumat
Public Domain: U.S. Department of Agriculture
CC BY-SA 2.0: Alpha