Leeks are part of the Allium family, and you can get different varieties as well as early, mid and late sowing types. This means that by using a mixture, you could extend and spread out your leek crop harvest time.
Leeks are best sown indoors, in modular trays first. Early seedlings will look very delicate like blades of grass. Leek beds can take up a fair amount of space with some being planted out during March-April and some later; during June-July. Leeks can be left in the ground until you need them, being careful that they do not become water-logged.
When your leek seedlings are approximately 6 inches and pencil-like, they can be planted outside. Transfer the stronger ones into a well-drained bed in a sunny position.
To encourage the width growth of the white part of the leek, use something like a tool handle or similar, to make a 6-inch, deep hole in the soil. Drop your leek into the hole and fill it with water. Do not fill up with soil. The leek will grow to the size of the hole made and as it grows further you can earth it up, being careful not to get soil in the leaves. You can offer them more support by adding a cardboard tube such as a toilet roll or similar whilst they are small.
Leeks can vary in size, and you can pull them up as and when required from late summer through to winter or even the following Spring if you have a late variety. Smaller leeks tend to be more tender.
Leeks will require watering during dry spells, but they do not like overly wet conditions, which causes rot.
Leeks can experience a few problems including rust where the leaves will develop orange rust-like patches on, which is a fungal disease. To avoid this, spread your leeks out giving them plenty of space when planting them out. Long wet spells can cause this and unfortunately, we cannot control the weather. It is important to use well-drained soil and protect them if necessary. If you only have a small rust issue on the leaves, you can probably still use them, but a more serious infection can ruin your crop.
Leaf miner is another common problem, where flies lay eggs in or near the plant and you will find track marks on the leaves and up the plant. You will find small brown pupae in the stems and bulbs. The plant will become dishevelled and rot if it is left. The best way to avoid leaf miner is to protect with fine mesh from early Spring. Leaf miner can be a problem for other vegetables in the Allium family such as onions and garlic.
You can begin to harvest your leeks during late summer or if you prefer larger, more mature leeks you can wait longer. Leeks can stay in the ground for some time, so there is no need to pull them all and store them, however they will be more prone to rot if it is a wet winter.
Leeks are such a flavoursome vegetable and can be frozen for later use. A particular favourite is leek and potato soup! Leeks are a great addition to casseroles and can be used as a tasty alternative to onions.