Growing Leeks

allium porrum : Amaryllidaceae / the onion family

Jan F M A M J J A S O N Dec
S S             S S    
    T T             T T

(Best months for growing Leeks in New Zealand - cool/mountain regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • Easy to grow. Grow in seed trays, and plant out in 4-6 weeks. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 46°F and 86°F. (Show °C/cm)
  • Space plants: 4 - 8 inches apart
  • Harvest in 15-18 weeks. Loosen with a fork rather than pull by hand..
  • Compatible with (can grow beside): Carrots
  • Almost ready to use
  • Leek

A member of the onion family. Looks rather like a large spring onion (scallion). Grow in seed trays or punnets until about 20 cm (8 in) tall. They look rather like large blades of grass at that stage. Then plant out into trenches or individual deep holes. The aim is to blanch the stems while the plants are growing. Trenches should be about 20 - 25 cm (8 - 10 in) deep. Set the seedlings 10 - 15 cm (4 - 6 in) apart then add enough soil to just cover the roots. As the plants grow fill the trench. Otherwise - make holes with a dibble or suitable stick 15 cm (6 in) deep and 3 - 4 cm (1.5 - 2 in) wide. Drop a seedling in each and water enough to cover the roots with soil. As they grow, watering will gradually fill the hole.

Leeks prefer moist clay soils. Keep soil moist and loose, mulch will help.

Culinary hints - cooking and eating Leeks

Trim off the roots and any damaged leaves.
Young ones can be used whole with some of the green leaves.
Wash thoroughly as the earth tends to get inside.
Chop and fry in butter (or olive oil) until tender.
Can be added to casserole meals, allowing time to cook through.
Leek and mushroom make a tasty combination for a tart filling.

Your comments and tips

23 Aug 22, Antoine Scriverner (New Zealand - cool/mountain climate)
Bertie, Try some keiserite.(magnesium sulphate) Its magic. But don't forget a good side dressing of super + blood & bone.
07 Apr 22, Murray Patterson (New Zealand - temperate climate)
Hi Annette, It appears that you may have Cutworm problems. I have had these in my garden and they cut the small plant at the base. I have now got around this by planting my small plants in toilet rolls which I place in the ground and have about 5 cm above ground. Around this I have cut a hole in some tinfoil paper and placed it over the toilet roll so it has what you could call a skirt over the ground and this has cured my cutworm problem. They do not seem to like it at all. As they come out at night to eat I think the foil has deterred them. Murray
15 Mar 20, Annette (New Zealand - temperate climate)
We planted out four leeks and this morning one is completely gone and another has a small piece of stalk left. What would be eating them? Thanks
16 Mar 20, Liz (New Zealand - temperate climate)
You probably have some hungry rabbits eating your leeks. Otherwise, when it is wet enough, slugs will chew them too.
20 Apr 19, Derek R (New Zealand - temperate climate)
I have just lifted a fantastic crop of leeks. They grew so easily which I didn’t expect through the summer months but so happy they did. Would it be ok to replant leeks in the same soil for winter.
24 Mar 19, Bertie (New Zealand - temperate climate)
My leeks never fatten up. I wonder why.
08 Jan 19, michelle (New Zealand - temperate climate)
Hi have just dug up leeks as they seemed to go woody and flower so quick this year. I found lots of bulbs underground are just like elephant garlic, some with babies. Do they behave like garlic? or am I just finding previous elephant garlic bulbs left behind that have sprouted or maybe none of them were the leek plants at all that I purchased ? confused Michelle
10 Jan 19, Mike (New Zealand - temperate climate)
Sounds like you planted them late in the season. Look at the guide here - maybe plant seed March and transplant 4-6 weeks later. Then harvest 11-13 weeks later. They should look like a leek not garlic. Do some research on the internet - how to grow leeks.
03 Dec 18, Genevieve Radley (New Zealand - temperate climate)
What season are leeks harvested in NZ? Thanks :)
04 Dec 18, Mike (Australia - sub-tropical climate)
Read the notes here about growing it. It tells you when to plant and how long until harvest.
Showing 1 - 10 of 16 comments

I always plant seeds on Nov 1st in a nursery bed ,use liquid feed to raise . Febuary I plant by the moon Calendar When planting I dib hole 150 mm deep ,place in two sheep pellets and water in . Trim tops and root before planting .If too hot cover in shade cloth, and water regulary until established. Have had good sucess in the past.

- lez Howard

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