How to Grow Leeks: Sweet Stalks That Stand Through Winter

GardenDraft Team · August 16, 2026 · Updated August 1, 2026 · 8 min read

Part of: Garden Planning Guides · How to Grow Vegetables — Crop Guides A–Z

Leeks are the patient gardener's onion. They ask for a long season and a little earthing-up, and in return they give you sweet, mild stalks that stand in the garden through hard frost and snow, ready whenever you want them. They never form a bulb, so there's no curing or storage fuss: you just pull them as needed, often right through winter. The one skill worth learning is how to grow that long, tender white shaft cooks prize.

Summer leeks or winter leeks

The leek catalog splits roughly in two. Summer types are quicker — the fast end of the catalog's range, around 75 to 95 days — taller and slimmer, milder, and meant to be eaten in late summer and fall rather than left standing. Winter types take 100 to 120 days or more, grow stockier with blue-green leaves, and are the ones that hold in frozen ground; the catalog rates leeks hardy to 5°F, the toughest thing in the allium family. A sensible plan is a few feet of each: summer leeks for cooking from August on, winter leeks as a standing larder. Elephant garlic, incidentally, is the same species grown for its bulb — a botanical cousin, not a true garlic.

Start early, grow long

Leeks are slow, needing a long season — often 100 days or more from seed — so most gardeners start seeds indoors in late winter, well before the last frost, and set them out in spring. Sow seed in a pot, and when seedlings are about pencil-thick and 6 to 8 inches tall, transplant them out. They're hardy and unbothered by cold, so they go out early and just keep growing all season. A fall harvest from a spring planting is the classic plan, and unlike onions, leeks don't care about day length, so the same approach works almost anywhere.

The catalog's numbers put the indoor start 10 to 12 weeks before transplanting, with setting-out time 2 to 4 weeks before last frost after a brief 5–7 day hardening off — so in a cold climate you're sowing leeks in February, among the first seeds of the year. Germination is on the slow side (the catalog's rated minimum is 60 percent, and a week or two to emerge is normal), so sow generously. Seedlings look like grass for a month; a trim to 4 inches with scissors once or twice keeps them stocky rather than floppy. Skip the trim in the last two weeks before transplanting so they go out with full reserves.

There's also a lower-effort seedling method worth knowing: multisowing. Sow three or four seeds per cell, skip all thinning, and transplant each little clump whole into a slightly wider hole. The leeks shoulder each other apart as they grow, you get three usable (if slimmer) shafts per station for a third of the transplanting work, and harvest is one fork-lift per clump. It trades maximum size for total yield — a good trade in most kitchens.

The trick: blanch the white shaft

That long white base isn't a variety trait: it's created by keeping light off the lower stem, which is the one technique that defines growing good leeks. The simplest method: at transplant, use a dibber to make a deep hole about 6 inches deep, drop one seedling into each, and just water it in without filling the hole — the hole fills gradually on its own and the shaft blanches white as it grows. As plants size up through the season, draw soil up around the stems (hilling) a little at a time to blanch even more. Plant in full sun in rich, loose soil and keep them evenly watered for the most tender stalks.

Space the dibber holes about 6 inches apart — that's also the catalog's square-foot value, four leeks per square, with slim summer types tolerating 4 inches (square-foot spacing chart). Rows a foot apart leave room to drag soil up at hilling time. When you hill, stop just below the point where the leaves fan apart, or you'll spend the winter rinsing grit out of dinner.

Feeding and watering a long-season crop

A leek sits in its bed for most of a year, so prepare it the way you'd prep for any heavy feeder: a generous layer of compost forked in, plus a nitrogen-rich feed once or twice in midsummer while the shafts are thickening (feeding basics). Alliums root shallowly, so an inch of water a week matters more than it looks like it should — drought makes thin, papery shafts — and a mulch tucked around the plants saves both water and weeding. Weeds are the other quiet yield-killer; leeks compete poorly, so keep the bed clean, especially in the grassy-seedling stage when a weed and a leek look identical.

Harvest leeks all winter

Leeks are ready whenever the shafts are usable, and there's no rush — they stand in cold ground for weeks or months without going to seed, so the garden becomes your storage. Lift them with a fork rather than yanking (the roots hold tight), and in many climates you can harvest right through winter under a mulch of straw, pulling fresh leeks while everything else is finished. Rinse well: soil and grit lodge between the layers of the shaft, so split and wash them thoroughly before cooking.

Where winters are brutal, dig a batch before the ground locks up and heel them into a bucket of damp sand in a cold shed — they'll hold for weeks. Any leeks still standing in spring will bolt as the weather warms; use them up first, or let one flower for the pollinators and collect seed from this easy seed-saving candidate.

Don't wait for full size to start eating, either. Baby leeks — anything from pencil to thumb thickness — are a delicacy in their own right, sweeter and quicker-cooking than the mature article, and pulling every second plant through late summer is a harvest schedule and a spacing plan rolled into one: the survivors inherit the room and fatten into your winter stand. Grill the babies whole, and the thinning trip starts feeling less like garden admin and more like the point. Any trimmed root ends with a half inch of base attached will even resprout in a pot, scallion-style, for a bonus round of greens.

Few problems

Leeks share onion-family pests like thrips and the occasional leek moth or onion maggot, but they're generally hardier and less trouble than onions, and their oniony scent helps deter pests from neighbors as a companion plant — the leek-and-carrot pairing has documented support, with the leek's sulfur volatiles masking the carrot rust fly's host-finding. Keep alliums moving in your rotation so soil diseases never build, and watch for orange-flecked rust in warm wet spells, which looks alarming but rarely costs much crop. Plan their long season on the planting calendar.