A smart guide to growing and cultivating leeks

The leek is a close relative of the onion. It resembles a giant scallion but has flat, broader leaves and different growing requirements. It does not store well out of the ground. The time to maturity for leeks is long — about four and a half months. Read on to learn more about growing healthy leeks in your vegetable garden.

• Leeks need fertile soil, so spread five to 10 centimetres (two to four inches) of compost over the soil and work it in well, or plant a green manure crop.
• Prepare the soil during the fall before planting so that the organic matter will be fully incorporated into the soil by spring planting time.
• Because the leek is grown for its long white bulb end, and the bulb will turn green and grow tough if exposed to sun, leeks are customarily planted in a trench so that the bulbs can be kept covered with earth.
• To prepare the trench, dig a furrow 15 centimetres (six inches) deep and 23 centimetres (nine inches) across.
• If you dig more than one trench, leave 30 to 60 centimetres (12 to 25 inches) between trenches.
• Clear the trench bottom of stones and clods.

Popular varieties of leek are 'American Flag', 'King Richard', and 'Tadorna'.

• Because leeks take 130 days to mature, the seeds are sown indoors in most areas, 10 to 12 weeks before the date of the last expected frost.
• Sow the seeds three centimetres (one inch) apart and three millimetres deep.
• When sprouts appear, thin them with clippers so that the remaining plants stand five centimetres (two inches) apart.
• When the seedlings are 10 centimetres (four inches) tall, drop them into holes made 10 to 15 centimetres (four to six inches) apart in the bottom of the trench, so that only the upper leaves stick partly out.
• As the leeks grow, heap the soil that you previously excavated for the trench around the lengthening bulbs.
• Leek seeds can also be sown directly into the garden as soon as the soil can be worked.
• Garden-sown leeks may not be fully mature by the fall, but they can be mulched to remain in the soil through the winter, then harvested the next spring
• .Plant leek seeds in a seedbed one centimetre (half an inch) deep in rows 15 centimetres (six inches) apart, and when the seedlings are 15 to 20 centimetres (six to eight inches) tall, transplant them to a trench.
• Cut half the leaf portion of each plant before transplanting; this lessens the shock in moving them.

• Cultivate leeks as you do onions, fertilizing them in midseason with compost tea or a fish fertilizer solution.
• Weed assiduously and carefully, as with onions.
• Leeks can be harvested long before full maturity.
• Dig up the plant with a spading fork.
• Store leeks in soil in your cellar, or leave heavily mulched in the garden for harvesting.
• Side shoots can be removed and transplanted to yield another crop.

• Onion maggots feed on onions and leek bulbs. Once they infest a crop, nothing will save it. But you can protect your crop with floating row covers when the plants are young.
• Thrips feed on the leaves, causing them to mottle and wither. Choose varieties with round leaves and an open habit.
• Use water sprays, garlic repellent sprays, or neem.

Growing leeks has never been easier! Keep this guide in mind and add the nutritious vegetable to your garden today.