Vegetable / Cool season
Leeks
A slow crop that pays off after the first frosts
Plant out byApr 13zone 6
- Family
- Amaryllis (Amaryllidaceae)
- Sun
- Full sun (6+ h)
- Difficulty
- Fussy
- Days to harvest
- 70-120 days
- Spacing
- 6 in apart, rows 18 in
- Pot size
- 5 gal pot (fine in pots)
- Frost
- Hardy
- Start
- Start indoors
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Wait until Jan 12
In zone 6, start seeds indoors Jan 12 to Feb 23; plant out Mar 30 to Apr 13. Average last frost Apr 20, first fall frost Oct 20.
Units
Leeks are the slow crop in the bed. Seeds go in indoors 8 to 10 weeks before the last frost, or 12 to 14 weeks in colder zones. After that, the plants still need 70 to 120 days in the ground. For weeks they look like blades of grass. You set them out in early spring and eat them once the frosts arrive.
The step most people skip is blanching, and it matters more than anything else here. The tender white shank only gets long if the stem grows in the dark. Set seedlings into a trench about 6 inches deep and leave it open at first. As they thicken to about pencil size, fill the trench, then hill soil up the stems every two or three weeks. Skip it and you get mostly green, chewy leaf. Grit works into the layers this way too, so rinse well before cooking.
Transplants go out 1 to 3 weeks before the last frost, once days reach about 45 degrees F. Give them 6 inches or a little more. Thrips, leek moth and leek rust are the usual problems, and rust-resistant varieties help. Leeks handle hard frost, and in zone 7 and warmer they can often stay put all winter. A deep pot holds a handful, though a bed row makes more sense for a crop that sits this long.
Things to consider
- A warm spell followed by cold can make leeks bolt, and so can oversized transplants or heavy feeding. Snap off flower stalks as soon as they show, since they change the flavor. Starting from small, pencil-thin transplants and feeding lightly both help avoid it.
- This crop ties up bed space for most of the year. In a small bed, run leeks along the north edge so they do not shade shorter neighbors. Quick lettuce or radishes can fill the gaps between young leeks before they bulk up. By the time the radishes are pulled, the leeks need the room.
- Short-season types such as 'King Richard' reach eating size in about 75 days. Long-season varieties take far longer, so choose by when you want to eat them, and ask your local extension office which hold best through your winter.
Good neighbours
Keep apart
Pests to watch for
ThripsLeek mothOnion maggots
Questions about growing leeks
Do I have to blanch leeks?
No, but the white part stays short without it. Hilling soil or planting in a trench gives longer, sweeter shanks. Stop hilling two to three weeks before you plan to dig. Some growers slip a cardboard tube over each stem instead, which keeps soil out of the layers.
Can leeks stay in the ground over winter?
In zone 7 and warmer they often can, since the tops do not die back like onions. In colder areas, a thick layer of straw buys some extra weeks. Dig the rest before the ground freezes solid. Leeks left into a second year will flower, so use them up before spring growth starts.
How do I get the dirt out from between the layers?
Cut each leek in half lengthwise and fan the layers under running water. Soil hides between the rings, especially on hilled plants, and one gritty bite ruins a pot of soup. Slicing first and swishing the rings in a bowl of water also works.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.