Marblemount, Washington, sits in USDA hardiness zone 8b — a zone band wide enough that plant choice, not possibility, is the interesting question.
A short list that earns its place here — cabbage, fig, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Marblemount, 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 Marblemount 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 Marblemount — soil, climate, flood, and parcel records. How we handle your address.
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Marblemount — the short answer
Marblemount, Washington: USDA zone 8b, about 231 days between hard freezes, across 2K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~231
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 8b is Marblemount's average, not your lot's — a low corner or a tree line moves it. Against Marblemount's 231-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Marblemount
Each reading below is measured for Marblemount itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMarblemount runs about 231 days between hard freezes — 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
MeasuredMarblemount sits in USDA hardiness zone 8b.
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 Marblemount is in
Marblemount sits in the North Cascades — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Marblemount's own centroid rather than borrowed from Skagit County.
What Grows in Marblemount
Every plant below cleared Marblemount's own zone 8b and its 231-day season. Each card opens that plant's Washington profile. How we score.
Is it too late to plant in Marblemount?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 16 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near Marblemount
Closest first, within ~10 miles of Marblemount. Listing isn't leaking, and distance isn't exposure.
- NORTH CASCADES NATIONAL PARK SVC COMPLEXBrownfields · 0.5 mi
- MARBLEMOUNT RANGER STATIONUnderground Storage Tanks · 0.5 mi
- MARBLEMOUNT CENTRAL 6636-057Underground Storage Tanks · 0.6 mi
- CHOM'S CHEVRONUnderground Storage Tanks · 0.7 mi
- SHIM SHELLUnderground Storage Tanks · 1.1 mi
- WA DFW SKAGIT SALMON HATCHERYUnderground Storage Tanks · 1.6 mi
- DIABLO LAKE RESORT INCUnderground Storage Tanks · 5.6 mi
- WA WSP ROCKPORTUnderground Storage Tanks · 7.8 mi
- MARBLEMOUNT SHOPUnderground Storage Tanks · 7.8 mi
- ROCKPORT PROPERTYUnderground Storage Tanks · 7.9 mi
- SKAGIT COUNTY RFA STATION 3Brownfields · 8.2 mi
- ROCKPORT STATE PARKUnderground Storage Tanks · 8.4 mi
2 more sites are on the record inside the same radius. See them on the map
Measured from Marblemount'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 Marblemount.
Severity Distribution
within ~10 miles of Marblemount
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Marblemount
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 Marblemount average
Your land is one point inside Marblemount
Everything above resolves to Marblemount as a whole — one PHZM band and one 28°F frost record, read across 2K acres. 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 Marblemount Average
Marblemount Average
- ●USDA Zones 8b, averaged across Marblemount
- ●One soil character for all of Marblemount
- ●Frost dates read at Marblemount's scale: Mar 30 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Marblemount's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Marblemount
Pull a site-specific report for your exact address in Marblemount, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Marblemount averages can't show:
We read public map data around Marblemount — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Marblemount average
How we know this about Marblemount
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 Marblemount’s own record; 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 Marblemount
When does frost risk typically end in Marblemount?
The last hard freeze (28°F) in Marblemount typically lands around Mar 30, 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 20.
When is the first frost in Marblemount?
The first hard freeze (28°F) in Marblemount typically arrives around Nov 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 2, so the watching starts about Oct 17 — about 231 days after the spring freeze cleared.
How long is the growing season in Marblemount?
Measured between 28°F hard freezes, Marblemount sees about 231 frost-free days — roughly Mar 30 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Nov 2, about 196 days.
Is the soil safe to grow vegetables in Marblemount?
The federal record around Marblemount is light — 14 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (12), the nearest Brownfields record about 0.5 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Marblemount?
From about Oct 17 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Marblemount's scale — its 8b band and its 231-day season. Your yard writes its own version of Marblemount'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 Marblemount’s own scale
6 of the readings below were taken at Marblemount's own scale — its own ~231-day season between 28°F freezes, the 2,369 acres it covers and 14 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Marblemount's own USDA hardiness band, zones 8bUSDA PHZM 2023
- Marblemount's own 28°F hard-freeze dates, about Mar 30 and Nov 16 and the ~231-day span between themNOAA 1991–2020 Climate Normals
- 14 documented contamination sites on the federal record near Marblemount, the closest Brownfields record about 0.5 miles out from the town centreFederal environmental registers
- Marblemount's boundary and the 2,369 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~231-day seasonGrowable Ground crop-matching engine
- The ecoregion at Marblemount's own centroid, the North CascadesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Marblemount's 2,369 acres read through its county's SSURGO summaryfrom Skagit County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Skagit 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 Skagit County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Marblemount's 2,369 acreswhy one lot differs from the next →
- Which side of Marblemount you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,369 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.5 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 Marblemount-wide figureread your own land →
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