How to grow... Leeks
Rocket Growing Guides
The great thing about leeks is that you get a nice long harvesting period. You can dig them up all through autumn and winter. They are nice and easy to grow too.
- Growing Advice
- Common Problems
- Chef's Corner
Sunny site with well dug soil
Leeks like a sunny, sheltered spot that doesn’t get too waterlogged. Fertile soil helps, so add plenty of compost before planting.
Great for raised beds
You can grow leeks really well in a raised bed or traditional veg plot, and also in pots – choose pots that are nice and deep, and oblong in shape works well.
How far apart?
15-20cm apart is about right. If you are short on space, you can plant them closer together and harvest alternate leeks earlier in the season as baby leeks.
How to plant leeks
To plant your leeks, make a hole with a dibber or pencil 15- 20cm deep and pop your leek plant in. Fill the hole with water and just allow it to soak away. This will draw enough soil over the plant to cover the roots and help to blanch the stems as the leek grows.
Don't forget to label the row
Label your rows so you know where your leeks are – they are easily lost when they are still young plants, especially if you have couch grass popping up.
Earth them up
Earth up (pull a little extra soil into a small mound around the leek) as they start to grow – this will give you leeks with more white on the stem.
Weeding and Watering
Keep leeks well watered during dry spells, and keep them weed-free as much as possible. Using an onion hoe for regular weeding is best as this allows you to get in amongst the plants without disturbing their roots.
When to harvest
Leeks can be harvested in autumn and winter as you want to use them in the kitchen. Use a garden fork to carefully pull them up without tearing them at the roots.
If you start to see orange-brown marks appearing on the foliage, it is probably leek rust. This fungal disease usually kicks in in late summer/autumn. If this is the case, it is best to pull up your leeks early and you can still eat them once affected foliage is removed. To prevent it in the future, try not to overcrowd plants, and do not use a liquid feed.
You may first see the silk-like cocoons on the leaves, followed by white patches where leaves have been eaten. The damaged leaves soon start to rot. It is more problematic in the south, and in early autumn. If it affects your crop, it is best to grow them under insect proof mesh next season. If you do see cocoons, wipe them off.
Allium Leaf Miner
If you see rows of white spots on the leaves, it is allium leaf miner. This is the first sign, so if you do see this you may have caught it early – check the plants for eggs and remove any you find! The flies lay their eggs, and the larvae eat the foliage. The areas that have been eaten soon start to rot. October/November tends to be the worst time. If they are a problem in your area, try growing under insect proof mesh next time.
If, when you cut your leeks, there is a particularly tough centre to the stalks, then it is most likely that you have harvested after they have started to flower. Remove the tough part (use it in stock) and eat the rest.
You should harvest leeks as you need them as they don’t store very well.
Ways to cook
Leeks love thyme. It’s a truly tasty combination and you can’t go wrong gently cooking chopped leeks in butter and adding handful of fresh thyme with a pinch of sea salt.
Use the greener, tougher parts of the leaves to make stocks.