Leek crop sheet


Leeks are a member of the onion family and are a welcome addition to the school garden over the winter when freshly dug vegetables are scarce. 

  • Estimated time: 30 minutes
  • Location: Outdoors & Indoors
  • School term: All year round
  • Level of experience: No experience needed
  • Subject(s): Science

Learning objectives

  • Learn how to handle and sow seeds
  • Learn to thin seeds to a specified distance
  • Learn what plants need to grow 
  • Learn when vegetables are ready to harvest


Organic matter or fertiliser should be incorporated at least one month beforehand. The soil, raised bed or planter should have already been cultivated and be weed free with a fine, crumbly texture ready for seed sowing.


Equipment needed

  • Rake or hand cultivator
  • Trowel and bamboo cane
  • Measuring stick
  • Seeds (check they are suitable to sow at that time of year)
  • Watering can with a rose
  • Enviromesh or horticultural fleece (if sowing under protection)
  • Label and pencil  
  • Dibber

Step by step

  1. Make a drill (channel) in the soil 1.5cm deep. Use a measuring stick to keep the drill straight if using a trowel or push a bamboo cane horizontally into the soil to the correct depth.
  2. Take one pinch of the leek seeds at a time and sprinkle them along the drill evenly until you have a continuous row of seeds. 
  3. Cover the seeds and firm the soil above with the back of a trowel. Water the drill using a watering can with a rose. Label the row and make another drill 30cm away and do the same again.
  4. When the seedlings are about 4cm tall, thin them out so there is about 2.5cm between each one. Keep watering the crops in dry weather and remove any weeds.
  5. When the leeks are pencil thick, transplant them into their final growing place. With a dibber, make a hole wider than the leek but only one third of the depth of the leek's stem.  The part of the plant growing below ground will become white or 'blanched'. Drop the young leek plant into the centre of the hole and tease a bit of loose soil around its roots. The leek plant will now grow to fill the hole.  
  6. Leeks can be earthed up like potatoes to produce longer white stems. Harvest leeks from October to April.

Hints & tips

  • Watch out for leek pests such as onion fly and leek moth. Leek rust which is a plant disease that looks like orange rust on the leaves. If you see any sign of this problem, remove and discard any affected plants.

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