Cold hardiness

Future

2050

2100

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.

Now

Zone 6b

USDA

Published baseline for this location from 1991-2020.

Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer

Well-suited

2050

Zone 7a

Plotwright

Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).

Well-suited

In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.

✓

Well-suited today and still thriving in 2050.

Heat tolerance

Future

2050

2100

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.

Loading AHS heat-zone data for this location...

Where this plant fits

Suitable across 45 ecoregions — 45 climate-resilient through 2070. Best matches first.

Appalachian mixed mesophytic forests

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Appalachian-Blue Ridge forests

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Arizona Mountains forests

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Atlantic coastal pine barrens

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Blue Mountains forests

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California coastal sage and chaparral

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Canadian Aspen forests and parklands

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Central Pacific Northwest coastal forests

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Central Tallgrass prairie

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Central-Southern Cascades Forests

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What it needs

Conditions

Light

Full sun

Water

Moderate water

Spacing

6"

Habit

Upright biennial onion-family vegetable grown as an annual, forming a fan of strap leaves above a blanched stalk

Care tips

•

Trench or mound soil up around the stems as they grow to lengthen the tender, blanched white stalk.

•

Plant in deep, rich, sandy, well-drained loam in full sun and keep moisture consistent through the season.

•

Harvest when the lower stem is about 1 to 1.5 inches across; leeks are cold-hardy and can be left in the ground into fall and winter.

Lifecycle

Planting

Start seed indoors in late winter and transplant out, or direct-sow, into deep, organically rich, sandy, well-drained loam in full sun. Grown in the U.S. as an annual; leek is a long-season cool-weather crop.

Transplanting

Set transplants into deep holes or a trench so the developing stalk is shaded and blanches white; firm soil gently around the base.

Early growth

Keep consistently moist during the growing season and feed an organically rich soil — Missouri Botanical Garden rates maintenance as high. Trench or mound (hill up) soil around the stems progressively to lengthen the tender, blanched white stalk.

Maturity

Plants grow in a fan-like structure to roughly 1.5 to 3 feet tall and about 1 foot wide, with an edible cylindrical white stalk rising about 6 to 10 inches above the soil. Harvest when the lower stems reach about 1 to 1.5 inches in diameter; leeks tolerate cold and can be left in the ground and harvested into fall and winter.

Propagation

Grown from seed. The species is biennial and rarely flowers in cultivation, so garden propagation is by seed each season rather than by saved bulbs.

Pollination

Pollination not applicable

Leek is harvested for its stalk and leaves long before flowering, and Missouri Botanical Garden PlantFinder notes it rarely flowers in cultivation, so pollination is not a factor in growing it as a vegetable. It is propagated from seed each season rather than depending on garden pollination.

For people

Edible

A culinary vegetable grown for its mild, sweet, oniony stalk and tender leaves — used in soups, stews, casseroles, salads, and stir-fries or eaten raw (Missouri Botanical Garden PlantFinder). The blanched white stalk is the prized edible portion.

Native range

AHS heat range

1-6

Climate notes

•

Missouri Botanical Garden PlantFinder lists Allium ampeloprasum (Porrum Group), leek, for USDA zones 2 to 11 in full sun with medium water, grown as an annual vegetable; it rarely flowers in cultivation.

•

Per Missouri Botanical Garden PlantFinder, leek is easily grown in deep, organically rich, medium-moisture, sandy, well-drained loams in full sun, and performs best with consistent moisture during the growing season; blanching the stems by trenching or mounding soil produces the longest white stalks.

•

Not native to North America — Missouri Botanical Garden gives the native range as temperate regions (the species originates in southern Europe, northern Africa, and western Asia and is naturalized widely). Grown here strictly as a cultivated cool-season vegetable.

In the designer

Growth over time

7-14" tall · 6-9" spread

Seedling and early leaf growth; thin, grass-like at first.

Design roles: Edible

Seasonal interest

Spring

Summer

Fall

Winter

Filled = the plant has seasonal interest · ▾ now = your current season

Leek

At a glance

Related products

Why it matters

Cold hardiness

Heat tolerance

Where this plant fits

What it needs

Lifecycle

Pollination

For people

Native range

Climate notes

In the designer

Seasonal interest

Sources & citations