edenhana

Lemongrass

A clumping, grass-like tropical perennial that is genuinely frost-tender, a hard frost can kill it outright, which limits reliable outdoor growing to Northland, Auckland and other consistently warm, sheltered spots. Elsewhere it does well in a large container that can be moved under cover over winter, or is grown as a warm-season annual. The tender lower few centimetres of each stem, once the tough outer leaves are peeled away, is the part used in cooking.

Sun
full sun
Water
moderate
Spacing
60cm
Harvest
Ready in 120-150 days
Difficulty
intermediate
Grows in
Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman
Expected yield
Several stems per clump, harvested as needed
Cost to grow
~$8 NZD
Grocery value
~$20 NZD
Mature height
1m
Evergreen
Yes
Common diseases
Root rot in poorly drained or waterlogged soil
Common pests
Aphids

When to plant by region

In Whangārei / Northland, Auckland, Tauranga / Bay of Plenty, Gisborne and Napier / Hawke's Bay: October-November. In Hamilton / Waikato, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson and Tasman: November.

Growing stages

  1. PlantingLate spring, once the soil has warmed

    • Wait until the soil has properly warmed before planting, as this is a tropical, frost-tender plant
    • Choose the warmest, most sheltered full-sun spot available, or plant in a large container
    • Outside the warmest northern regions, growing in a container that can be moved under cover over winter is the more reliable option
    • Space plants around 60cm apart to allow for their clumping spread
  2. Establishment

    • Water regularly while the clump establishes; moderate, consistent moisture suits it best
    • Watch for aphids sheltering among the base of the leaves
    • Growth is slow to start but speeds up once the clump is established
  3. Ongoing growth & harvest120-150 days to first usable stems

    • Harvest outer stems at the base once they reach pencil thickness, leaving the centre of the clump to keep growing
    • Poorly drained or waterlogged soil is the main risk to the roots
    • Divide congested clumps every couple of years to keep the plant productive
  4. Overwintering

    • A hard frost can kill the plant outright, not just damage the leaves
    • In cooler regions, move container-grown plants under cover or into a sheltered spot before the first frosts
    • In mild, frost-free areas the clump simply slows down over winter and resumes growth in spring