Makrut lime
Citrus hystrix
Also known as: Kaffir lime (term increasingly avoided due to slur origin), Thai lime, Makrut, Bai makrut (the leaves), Magrood
Quick facts
- Category
- herbs woody
- Difficulty
- intermediate
- Days to harvest
- 365 to 730 days
- Harvest type
- continuous production over weeks or months
- Spacing
- 150 cm between plants
Environment
- Temperature
- 15–35°C
- pH
- 5.5 to 7
- EC (hydroponic)
- 1.4 to 2 mS/cm
- Daily light
- 20 to 30 mol/m²/day (strict, will fail outside this range)
Climate and zones
- USDA zones
- 9 to 12 (winter low around -7°C or warmer)
- Frost tolerance
- frost sensitive (dies at first frost)
- Season
- warm (summer crops, frost-sensitive)
Viable growing environments:
- outdoor in growing season (annual)
- unheated greenhouse / hoop house
- heated greenhouse
- indoor (heated home)
USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.
Growing systems
Makrut lime works in:
- soil bed
- media bed (ebb and flow)
Root mass is heavy - thin-channel systems (NFT, vertical towers) can't hold this crop mechanically, hence the system list above.
Growing media
The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (makrut lime works in the media listed below).
| Medium | pH effect | Water retention | Bacterial surface |
|---|---|---|---|
| Soil-based mix (Potting soil) | varies by source | high | high |
Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.
Nutrient demand by stage
NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.
| Stage | N | P | K | EC target (mS/cm) |
|---|---|---|---|---|
| seedling | 2 | 1 | 1 | 1 |
| vegetative | 2 | 1 | 2 | 1.6 |
Aquaponics suitability
Not recommended for pure aquaponics. Fish waste alone doesn't provide enough of the nutrients this crop demands (typically potassium, calcium, or boron). It can be grown in a hybrid system where the reservoir is supplemented with hydroponic-style nutrients, but expect to dose actively.
Care notes
An excellent container citrus tree for greenhouse growing, providing a continuous supply of one of the most important Thai and Southeast Asian cooking ingredients. Large container (20 L) with well-drained media. EC 1.5-2.5 mS/cm. pH 5.5-6.5. Temperature: 15–32°C (tropical origin; protect from frost). High light (DLI 16-28 mol/m2/day; supplemental lighting helps in northern climates). The tree grows slowly but produces harvestable leaves within the first year from nursery stock. Pick individual leaves as needed; the tree replaces them continuously. The leaves freeze well: pack flat in freezer bags and use directly from frozen (they shatter easily for shredding when frozen, which is convenient). Citrus-specific micronutrient supplementation (iron chelate, manganese, zinc) prevents yellowing. Scale insects and spider mites are the main pests. The thorns are sharp; handle with care. For anyone who regularly cooks Thai, Indonesian, or Malay food, a kaffir lime tree is one of the most valuable plants you can own.
Verified against: kasetsart-u, u-of-california-davis, u-florida-ifas. Last reviewed 2026-05-15.