garlic (Allium sativum), photographi

Can I Grow Garlic in Washington?

USDA Zones 4a-9b · Plant zone range 2-10

Yes — Strong Match

garlic (zones 2-10) covers every zone Washington contains (4a-9b), so hardiness is not what limits it anywhere in the state.

Garlic in Washington — the short answer

Garlic in Washington: hardy in zones 2–10, full sun, against a state median of ~208 frost-free days.

Plant zones
2-10
Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
Washington zones
4a-9b
USDA PHZM 2023
Frost window
Mar 16 - Apr 15 – Oct 24 - Nov 18
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
131 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
220 days
Growable Ground Plant Database

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free

Your yard isn't the whole zone.

Washington spans zones 4a-9b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score garlic against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Washington is not one climate

Washington’s winter-low ladder runs across 39 counties, from zone 6 in Ferry County to zone 9 in San Juan County. That is 30°F between the two counties’ average coldest night — the difference between garlic overwintering in the ground and coming under cover.

6 zonesFerry County9 zonesSan Juan County

The middle half of 39 counties runs 78.5 zones, with a median of 7 zones — a 3-zone span end to end.

Measured across 39 Washington counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Washington Fits Best

Even within Washington's zones 4a-9b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for garlic (USDA PHZM 2023):

Zone Comparison

Garlic Needs

  • USDA Zones: 2-10
  • Frost-Free Days: 90+
  • Sun: Full Sun
  • Mature size: 2 ft tall
  • Picking window: ~14 days of harvest
  • Drought tolerance: Medium

Washington Has

  • USDA Zones: 4a-9b
  • Last Hard Freeze (28°F): Mar 16 - Apr 15
  • First Hard Freeze (28°F): Oct 24 - Nov 18
  • Annual Rainfall: 6-90 inches
  • Common Soils: Volcanic ash, Silt loam (Palouse), Sandy loam

Plant Zone Range (zones 2-10)

2a
10b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.08.5

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Garlic in Washington

The frost window

Across Washington, the last spring hard freeze (28°F) clears between Mar 16 and Apr 15, and the first fall hard freeze lands between Oct 24 and Nov 18 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 192-day window you can count on — up to 247 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Garlic is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Washington's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.

Establishment timing

As a long-lived plant, garlic isn't racing the calendar to a harvest date. Plant it in spring once the last hard-freeze window passes so roots settle in through the full season, or in early fall while the soil still holds summer warmth.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says garlic survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Garlic wants 90+ frost-free days; a typical Washington site sees ~208 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Garlic needs ~1200 GDD (base 50°F) to ripen. The state median runs ~1740 GDD (from PRISM 1991-2020 climate normals), so Washington's typical season clears that easily.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Garlic tolerates a wide pH range (pH 5-8.5) — 3.5 units, acid ground through alkaline — so soil acidity is rarely what limits it in Washington. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 6 and 6.6 — worth knowing before you decide whether a Washington soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Washington site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Washington soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant garlic for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before garlic goes in. What follows is Washington’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Washington — and how to grow with it.

Federal record: High

We checked the federal record across Washington33,912 documented sites across 8 of the 9 source types we track.

The most significant on record: 329 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Washington carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Severity Distribution

across Washington

High874Moderate14,834Low18,204

Highest-Severity Sites

A and C
Mining Sites · Past Producer
Airway Heights City of
PFAS Sampling · PFAS Detected
Abe Lincoln
Mining Sites · Unknown
Aces Up
Mining Sites · Past Producer
Addie B
Mining Sites · Unknown

A note from Gnorman

What an experienced grower watches for around here

In and around Washington, Mining runs higher than the national average — 3,881 sites across Washington. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.

Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Garlic in Washington

Zone compatibility tells you about winter cold survival — but Washington growers also need to think about:

Extreme rain divide: 90+ inches west, 6 inches east of Cascades

East side requires irrigation — no rain from June through September

Slug and root rot pressure on the wet west side

Short seasons at elevation in the Cascades and northeast corners

What to actually do about these — and the constraints that apply to every Washington grower, not just garlic — is covered on the Washington growing guide.

Timing shifts within Washington

Garlic needs about 90 days of frost-free season to complete its cycle. Even Whatcom County — Washington’s shortest season at 131 frost-free days — clears that by 41 days, so season length isn’t the constraint anywhere in Washington. What varies is your own parcel.

Across Washington’s 39 counties the frost-free season runs from 131 days in Whatcom County to 300 days in San Juan County — a spread of 169 days, which is why a single statewide planting date misleads. The median Washington county sees 208 frost-free days, leaving garlic about 118 days of slack on a typical parcel — room for a second sowing where the season runs long.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Garlic's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Garlic draws honeybees, native bees, and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, garlic can only work that bloom inside Washington's frost window — roughly 208 days, opening after the last 28°F freeze (Mar 16 - Apr 15) and closing at the first (Oct 24 - Nov 18), per NOAA Regional Climate Centers ACIS, 1991-2020. Deer pressure is meaningful across much of Washington; garlic is listed as deer-resistant (USDA PLANTS Database), which makes it a safer pick for unfenced sites. Our deer & wildlife guide carries the full deer-resistant list and how to protect the rest.

Washington Cooperative Extension

For Washington-specific cultivar recommendations, planting calendars, and pest pressure for garlic, the canonical source is WSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Garlic native to Washington?

No — the USDA PLANTS Database lists Garlic as introduced rather than native in the Lower 48, so it is not part of Washington's native flora. It grows here as a garden plant; pairing it with a few Washington natives keeps local pollinators fed too.

Looking for plants that belong here? The Washington growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Garlic in Washington

When can I plant Garlic in Washington?

Washington's last spring hard freeze (28°F) clears between Mar 16 and Apr 15, and the first fall hard freeze lands between Oct 24 and Nov 18 (NOAA Regional Climate Centers ACIS, 1991-2020). Garlic is a long-lived planting, so target spring just after your local last hard freeze — or early fall while the soil holds warmth — and let it establish through the season.

What hardiness zone is Garlic grown in across Washington?

Washington spans USDA hardiness zones 4a-9b (USDA ARS PHZM 2023). Garlic carries a range of zones 2-10, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Washington site have?

A typical Washington site sees ~208 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Garlic needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Garlic native to Washington?

No — the USDA PLANTS Database lists Garlic as introduced rather than native in the Lower 48, so it is not part of Washington's native flora. It grows here as a garden plant; pairing it with a few Washington natives keeps local pollinators fed too.

How should I amend the soil for Garlic in Washington?

Garlic tolerates pH 5-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 3.5-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Washington site — amend for drainage and organic matter first.

Will Garlic actually grow on my specific land in Washington?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores garlic against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Washington

State-level data is a sketch. Your Growable Ground report scores garlic against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Washington garlic averages can't show:

Your soil pHYour frost-free days — Washington averages 208Your sun & shade

We read public map data around Washington — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Washington garlic average

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