How to Grow Leeks: The Complete Guide (2024)

FAQs

How to Grow Leeks: The Complete Guide? ›

Plant leeks in a sunny spot in soil that is fertile and well-drained. Leeks thrive in traditional garden beds, raised beds, or even in tall containers, so choose whatever works best for you. Space leeks 6 inches apart when planting. Leeks need two things to thrive: lots of nitrogen and consistent soil moisture.

For a bumper crop, improve your soil by digging in two buckets of garden compost or well-rotted manure per square metre/yard, especially if you have lighter, free-draining soil. Leeks don't do well in very acidic soil (below pH 6), so if necessary reduce acidity by adding lime in autumn or winter.

Companion planting for health and yield

Plant leeks with carrots, celery, onions and spinach for improved growth. But, steer clear of planting them near beans and peas. The leeks will benefit the other veg by repelling carrot root fly.

Most leeks require a long growing season of about 120 to 150 days. Start seeds indoors and transplant in early spring. Hill the plants to produce a longer white shaft, or plant in a furrow and fill it in. Leeks have shallow root systems and need plentiful watering.

Leeks are related to green onions so it should be no surprise they can be regrown in the same way (and just as easily). Cut off the root and about 2" of the white part. Regrow in a jar with water reaching halfway up the leek. Leeks will take longer to grow because they are much larger than green onions.

Water leeks as needed until plants are established. After that, plants require an inch of water a week, either through rainfall or irrigation. Inconsistent moisture yields tough stems. As leeks grow, mound the soil from the trench around stems, beginning when stems are 1 inch thick.

Caring for your Crop

Ideally you should also add fertilisers such as fish, blood & bone (if organic) or liquid feeds such as Miracle Gro or Phostrogen as leeks are nitrogen intense.

Strawberries seem to enjoy living next to leeks, and the strong odor of the leeks repels many pests of the berries. Other leek plant companions might be cabbage, tomatoes, beets, and lettuce. The leafy vegetables, especially, seem to benefit from the strong scent of plants in the Allium family.

I grow several varieties, sowing a spring crop to eat from late summer into winter and a fall crop to enjoy in spring. Leeks grow superbly in cool, rainy places. They don't mind warmer, drier climates, though, when pampered with lots of water and thick layers of mulch to keep the soil cool and the weeds at bay.

Onions (Allium cepa), leeks (Allium ampeloprasum) and garlic (Allium sativum), too, are plants that grow well with tomatoes. They keep away whiteflies (Bemisia sp.) from the surface and can even drive away voles from your garden bed.

What is the best fertilizer for leeks? ›

Fertilization. In addition to any fertilizer used at planting, leeks need additional nitrogen to produce optimum yields. Side dress with nitrogen at ¼ lb. (21-0-0) per 100 square feet in mid-May and again in late June.

Planting leeks facts

Biennial (a plant that requires two growing seasons to complete its life-cycle) but treated as an annual. Planting: Start seeds indoors for early spring transplants or later in the summer for a fall crop. Leeks are fairly hardy and can be planted several weeks prior to the last frost date.

They do best in full sun in light, well-drained soil. They are more successful in heavier soils than onions. They are also a rather long-season crop (80-120 days).

Leek is an expensive crop to grow, because it is labor intensive. Hand labor is required for all stages of production including: transplanting, weeding, harvesting, washing and packing.

Leaves which grow too long can be trimmed back slightly so that they do not rest on the ground.

The first thing to do to stop bolting leeks is to plant at the right time. While leeks can survive freezing temperatures, they will be more prone to go to seed later on if they are exposed to freezing temperatures. This means that you should plant leeks after daytime temperatures are consistently above 45 degrees F.

I recommend trimming off at least half of the uppermost dark green leek pieces: At the very top, they're pretty leathery and just not that tasty. But the lowest inch or two of dark green pieces - right where the dark green meets the white portion of the vegetable - are much more tender and easier to cook with!

Sow seed in pots or modules of peat-free seed or multi-purpose compost in spring. Keep pots moist and plant out in summer, either individually, using a dibber, or in small clumps. Harvest leeks from autumn. Some varieties are hardy and can be harvested right through to spring.