Des Moines, Washington, sits in USDA hardiness zone 9a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, kale, potato, garlic, and western red cedar all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Des Moines, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Des Moines lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Des Moines — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Des Moines — the short answer
Des Moines, Washington: USDA zone 9a, about 252 days between hard freezes, across 4K acres of city.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 14
- King County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 21
- King County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~252
- King County normal — NOAA 1991–2020, nearest to this town
- City area
- 4K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are King County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Des Moines's average, not your lot's — a low corner or a tree line moves it. Against Des Moines's 252-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Des Moines
Each reading below is measured for Des Moines itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsDes Moines runs about 252 days between hard freezes (read from King County, the closest normal to Des Moines) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredDes Moines sits in USDA hardiness zone 9a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Des Moines is in
Des Moines sits in the Puget Lowland — EPA Level III, inside the wider Marine West Coast Forest. That is read at Des Moines's own centroid rather than borrowed from King County.
What Grows in Des Moines
Plants matched to Des Moines's USDA zones 9a, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in Des Moines?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Des Moines
Closest first, within ~10 miles of Des Moines. Listing isn't leaking, and distance isn't exposure.
- 22N/04E-17Q04Nitrate · 1000 ft
- KING COUNTY WATER DISTRICT #54PFAS · 1200 ft
- HIGHLINE WATER DISTRICTPFAS · 1200 ft
- BROWN BEAR CAR WASH DES MOINESUnderground Storage Tanks · 0.7 mi
- JOHNNYS FOOD CENTERUnderground Storage Tanks · 0.7 mi
- UNOCAL 4218Underground Storage Tanks · 0.7 mi
- DES MOINES SEWER DISTRICTUnderground Storage Tanks · 0.8 mi
- HIGHLINE SD MOUNT RAINIER HIGH SCHOOLBrownfields · 0.8 mi
- HIGHLINE COMMUNITY COLLEGEBrownfields · 0.8 mi
- HIGHLINE COMMUNITY COLLEGEUnderground Storage Tanks · 0.9 mi
- HOWARD E BUTLERUnderground Storage Tanks · 0.9 mi
- CSR MARINE SOUTHBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Des Moines's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Des Moines.
Sources Checked
within ~10 miles of Des Moines
Severity Distribution
within ~10 miles of Des Moines
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Des Moines, two things run higher than the national average within ~10 miles of Des Moines — Superfund (43 sites) and Toxics Release Inventory (164 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Des Moines
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Des Moines average
Your land is one point inside Des Moines
Everything above resolves to Des Moines as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from King County’s record because no 30-year normal resolves at this city’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Des Moines Average
Des Moines Average
- ●USDA Zones 9a, averaged across Des Moines
- ●One soil character for all of Des Moines
- ●Frost dates read at Des Moines's scale: Mar 14 to Nov 21
YOUR Parcel
- ✓Your exact zone, not Des Moines's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Des Moines
Pull a site-specific report for your exact address in Des Moines, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Des Moines averages can't show:
We read public map data around Des Moines — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Des Moines average
How we know this about Des Moines
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at King County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Des Moines
When does frost risk typically end in Des Moines?
The last hard freeze (28°F) in Des Moines typically lands around Mar 14, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 4.
When is the first frost in Des Moines?
The first hard freeze (28°F) in Des Moines typically arrives around Nov 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 7, so the watching starts about Oct 22 — about 252 days after the spring freeze cleared.
How long is the growing season in Des Moines?
Measured between 28°F hard freezes, Des Moines sees about 252 frost-free days — roughly Mar 14 through Nov 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 4 to Nov 7, about 217 days.
Is the soil safe to grow vegetables in Des Moines?
The federal record around Des Moines runs heavier than most — 2,381 documented sites, mostly Underground Storage Tanks entries (1,383), the nearest Nitrate record about 0.2 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Des Moines?
From about Oct 22 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 21 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Des Moines's scale — its 9a band and its 252-day season. Your yard writes its own version of Des Moines's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Des Moines’s own scale
4 of the readings below were taken at Des Moines's own scale — the 4,105 acres it covers and 2,381 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Des Moines's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 2,381 documented contamination sites on the federal record near Des Moines, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Des Moines's boundary and the 4,105 acres inside itUS Census TIGER/Line 2025
- The ecoregion at Des Moines's own centroid, the Puget LowlandUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Des Moines has no normal of its own, so its county's is the closest measured readfrom King County
- Soil character — no town-scale survey exists, so Des Moines's 4,105 acres read through its county's SSURGO summaryfrom King County
- The candidate plant list — Washington's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom Washington
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom King County
- The growing challenges every Washington grower plans around — written at state scale, so they stay on the state guidefrom Washington
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom King County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Des Moines's 4,105 acreswhy one lot differs from the next →
- Which side of Des Moines you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,105 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Des Moines-wide figureread your own land →
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