Leeks are one of the most traditional, easy to grow, and delicious vegetables to be found on allotments.
They grow in nearly all soil types – but grow biggest in rich soils – and are relatively disease free and extremely hardy. This last property is one of the main reasons to grow them. Leeks can be left on the plot to mature through winter and early spring and simply picked when needed.
- February – May
- Planting depth: 1 cm (before transplanting to holes 6 inches deep)
- Planting spacing: 15cm between leeks, 25 cm between rows
- September – May
- Eat fresh and sow in succession to extend harvest period
Leeks are the largest member of the allium family that includes onions, garlic, and chives. Rather than form a bulb, their leaves grow straight upwards wrapped tightly around each other to create what looks like a stalk, but isn’t.
This is significant for the cook. It is very easy when growing leeks to splash soil between the leaves – if this happens the cook will need to chop the leeks finely and then wash thoroughly in a colander. The effort is well worth it. The distinctive, strong and sweet taste of leeks make them excellent for soups and risottos.
Leeks are healthy too, containing good amounts of fibre, magnesium, and vitamins A, B6, and C.
Leeks need a little warmth to get going, so the best time to sow leeks is after the weather turns warmer in spring, or earlier if you have a greenhouse. They should be sown in a seed tray, or in a plastic pot, so that they can be easily cared for before they are ready to be planted out.
Leeks are slow growing. If you are able to sow early it is possible to achieve a harvest by the autumn. Most commonly, leeks are sown for a winter or early spring harvest, as their hardiness means they are one of the few vegetables available on an allotment at that time of year.
I think transplanting is the fun part of growing leeks, and once you know how, straightforward.
The edible parts of leeks are the white base and light green stem (the shank), and ideally this should be a good length of at least 6″ or 15cm. To achieve this leeks should be planted in holes, as the exclusion of light is the key to achieving long shanks. For extra long shanks, earth up the stems as the plant grows.
Leeks are ready to transplant in late spring or early summer when they are 7-8″ high or 18-20 cm. Use a thick stick, the handle of a trowel, or similar, to create a hole about 6″ / 15 cm deep. The seedlings can be removed from a seed tray or pot by first watering in situ, and then gently lifting from underneath and shaking the soil off the roots.
Each individual seedling gets its own hole. The seedling should be placed in the hole with as much root as possible at the bottom. All that remains is to water them in, by filling the hole with water. This will cause a puddle in the hole, surrounding the roots with soil – and the job is done! You do not need to trim the roots or leaves before planting in the hole, although some people prefer to do this.
You will need to regularly hoe around your leeks to ensure they get enough light. Notwithstanding this, leeks are very easy to take care of. There is no need to water them during the summer months, unless it is exceptionally dry, and they have very few diseases, or bugs that eat them. If you notice any flower stems (leaves with buds on) these should be removed.
Best of all, when ready, there is no need to store leaks as they can left in situ until you are ready to eat them. Unlike parsnips, it is easy to find leaks when your plot is covered in snow! If so inclined, you may like to leave some plants in the ground for spring.
I like to leave a plant or two on the plot to produce flowers in early summer. Leeks produce large beautiful flowers that are good to look at, and loved by bees.
Leek varieties differentiate based on their speed of growth, length of stem, and winter hardiness.
Early varieties are smaller but have a faster growth cycle. Late varieties take longer to mature and are harvested in the winter months.