Markham, Washington, sits in USDA hardiness zone 9a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: artichoke, fig, california poppy, and cabbage. The site-level story — soil, sun, drainage — decides the rest.
Even in Markham, 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 Markham 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 Markham — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Markham — the short answer
Markham, Washington: USDA zone 9a, about 256 days between hard freezes, across 719 acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 9
- Grays Harbor County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 20
- Grays Harbor County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~256
- Grays Harbor County normal — NOAA 1991–2020, nearest to this town
- Town area
- 719 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 Grays Harbor County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Markham's average, not your lot's — a low corner or a tree line moves it. Against Markham's 256-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Markham
Each reading below is measured for Markham itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMarkham runs about 256 days between hard freezes (read from Grays Harbor County, the closest normal to Markham) — 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
MeasuredMarkham 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 Markham is in
Markham sits in the Coast Range — EPA Level III, inside the wider Marine West Coast Forest. That is read at Markham's own centroid rather than borrowed from Grays Harbor County.
What Grows in Markham
Every plant below cleared Markham's own zone 9a and its 256-day season. Each card opens that plant's Washington profile. How we score.
Is it too late to plant in Markham?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 20 — 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 Markham
Closest first, within ~10 miles of Markham. Listing isn't leaking, and distance isn't exposure.
- OCEAN SPRAY MARKHAMToxics Release Inventory · 0.8 mi
- OCEAN SPRAY MARKHAMBrownfields · 0.8 mi
- OCEAN SPRAY CRANBERRIES INCUnderground Storage Tanks · 0.9 mi
- WA DOC STAFFORD CREEK CORRECTIONS CTRBrownfields · 3.6 mi
- INDEPENDENT DISTRIBUTORS INCUnderground Storage Tanks · 4.9 mi
- BOWERMAN AIRFIELDUnderground Storage Tanks · 5.0 mi
- BOWERMANUnderground Storage Tanks · 5.0 mi
- USCG STATION GRAYS HARBORBrownfields · 5.5 mi
- OCEAN COLD LLC WESTPORTToxics Release Inventory · 5.6 mi
- BAYVIEW CEDAR PRODUCTS INCUnderground Storage Tanks · 5.6 mi
- BILLS SHELL SERVICEUnderground Storage Tanks · 5.7 mi
- WESTPORT CITY HALLUnderground Storage Tanks · 5.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Markham'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 Markham.
Total Sites
238
within ~10 miles of Markham
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Markham
Severity Distribution
within ~10 miles of Markham
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Markham, two things run higher than the national average within ~10 miles of Markham — PFAS (3 sites) and Underground Storage Tanks (183 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Markham
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 Markham average
Your land is one point inside Markham
Everything above resolves to Markham as a whole — one PHZM band, read across 719 acres, with hard-freeze dates borrowed from Grays Harbor County’s record because no 30-year normal resolves at this town’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 town 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 Markham Average
Markham Average
- ●USDA Zones 9a, averaged across Markham
- ●One soil character for all of Markham
- ●Frost dates read at Markham's scale: Mar 9 to Nov 20
YOUR Parcel
- ✓Your exact zone, not Markham's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Markham
Pull a site-specific report for your exact address in Markham, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Markham averages can't show:
We read public map data around Markham — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Markham average
How we know this about Markham
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Grays Harbor 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 town grain anywhere on this page — there is no town-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 Markham
When does frost risk typically end in Markham?
The last hard freeze (28°F) in Markham typically lands around Mar 9, 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 Mar 30.
When is the first frost in Markham?
The first hard freeze (28°F) in Markham typically arrives around Nov 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 6, so the watching starts about Oct 21 — about 256 days after the spring freeze cleared.
How long is the growing season in Markham?
Measured between 28°F hard freezes, Markham sees about 256 frost-free days — roughly Mar 9 through Nov 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 30 to Nov 6, about 221 days.
Is the soil safe to grow vegetables in Markham?
The federal record around Markham is a meaningful one — 238 documented sites, mostly Underground Storage Tanks entries (183), the nearest Toxics Release Inventory record about 0.8 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Markham?
From about Oct 21 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Markham's scale — its 9a band and its 256-day season. Your yard writes its own version of Markham'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 Markham’s own scale
5 of the readings below were taken at Markham's own scale — the 719 acres it covers and 238 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Markham's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 238 documented contamination sites on the federal record near Markham, the closest Toxics Release Inventory record about 0.8 miles out from the town centreFederal environmental registers
- Markham's boundary and the 719 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~256-day seasonGrowable Ground crop-matching engine
- The ecoregion at Markham's own centroid, the Coast RangeUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Markham has no normal of its own, so its county's is the closest measured readfrom Grays Harbor County
- Soil character — no town-scale survey exists, so Markham's 719 acres read through its county's SSURGO summaryfrom Grays Harbor County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Grays Harbor 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 Grays Harbor County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Markham's 719 acreswhy one lot differs from the next →
- Which side of Markham you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 719 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Toxics Release Inventory record about 0.8 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 Markham-wide figureread your own land →