Marietta-Alderwood, Washington, sits in USDA hardiness zone 8b — 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: kale, potato, garlic, and western red cedar. The site-level story — soil, sun, drainage — decides the rest.
Even in Marietta-Alderwood, 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 Marietta-Alderwood 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 Marietta-Alderwood — soil, climate, flood, and parcel records. How we handle your address.
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Marietta-Alderwood — the short answer
Marietta-Alderwood, Washington: USDA zone 8b, about 131 days between hard freezes, across 4K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 29
- Whatcom County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Oct 7
- Whatcom County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~131
- Whatcom County normal — NOAA 1991–2020, nearest to this town
- Town 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 Whatcom County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Marietta-Alderwood's average, not your lot's — a low corner or a tree line moves it. Against Marietta-Alderwood's 131-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Marietta-Alderwood
Each reading below is measured for Marietta-Alderwood itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMarietta-Alderwood runs about 131 days between hard freezes (read from Whatcom County, the closest normal to Marietta-Alderwood) — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMarietta-Alderwood 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 Marietta-Alderwood is in
Marietta-Alderwood sits in the Puget Lowland — EPA Level III, inside the wider Marine West Coast Forest. That is read at Marietta-Alderwood's own centroid, and it is not what its county reads: Whatcom County is mostly North Cascades. The wider page above you is answering a different question about different ground.
What Grows in Marietta-Alderwood
Plants matched to Marietta-Alderwood's USDA zones 8b, 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 Marietta-Alderwood?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around May 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
What's on the federal record near Marietta-Alderwood
Closest first, within ~10 miles of Marietta-Alderwood. Listing isn't leaking, and distance isn't exposure.
- FORT BELLINGHAM MARKET & DELIUnderground Storage Tanks · 1900 ft
- FSS FLIGHT SERVICE STA BLIUnderground Storage Tanks · 2600 ft
- FUDS BELLINGHAM AAFBrownfields · 0.8 mi
- ALPHA HANGER 1Underground Storage Tanks · 1.0 mi
- WASHINGTON ANG 262 CCSQUnderground Storage Tanks · 1.0 mi
- WA MILITARY ORGANIZATIONAL MAINTENANCE SHOP 7Underground Storage Tanks · 1.0 mi
- BAKERVIEW AIRCRAFT MAINTENANCEUnderground Storage Tanks · 1.1 mi
- PUGET SOUND TRUCK LINES INC BELLINGHAMUnderground Storage Tanks · 1.1 mi
- 7-ELEVEN 39616AUnderground Storage Tanks · 1.1 mi
- ALASKA AIRLINES BELLINGHAMBrownfields · 1.1 mi
- BELLINGHAM INTERNATIONAL AIRPORTUnderground Storage Tanks · 1.1 mi
- WHATCOM COUNTY FIRE DISTRICT #8, STATION 33Brownfields · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Marietta-Alderwood'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 Marietta-Alderwood.
Total Sites
774
within ~10 miles of Marietta-Alderwood
Risk Level
Elevated
Highest-severity
7 Superfund sites
Sources Checked
within ~10 miles of Marietta-Alderwood
Severity Distribution
within ~10 miles of Marietta-Alderwood
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Marietta-Alderwood, two things run higher than the national average within ~10 miles of Marietta-Alderwood — CAFO (32 sites) and Nitrate (250 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Marietta-Alderwood
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 Marietta-Alderwood average
Your land is one point inside Marietta-Alderwood
Everything above resolves to Marietta-Alderwood as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from Whatcom 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 Marietta-Alderwood Average
Marietta-Alderwood Average
- ●USDA Zones 8b, averaged across Marietta-Alderwood
- ●One soil character for all of Marietta-Alderwood
- ●Frost dates read at Marietta-Alderwood's scale: May 29 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Marietta-Alderwood's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Marietta-Alderwood
Pull a site-specific report for your exact address in Marietta-Alderwood, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Marietta-Alderwood averages can't show:
We read public map data around Marietta-Alderwood — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Marietta-Alderwood average
How we know this about Marietta-Alderwood
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 Whatcom 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 Marietta-Alderwood
When does frost risk typically end in Marietta-Alderwood?
The last hard freeze (28°F) in Marietta-Alderwood typically lands around May 29, 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 Jun 19.
When is the first frost in Marietta-Alderwood?
The first hard freeze (28°F) in Marietta-Alderwood typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 131 days after the spring freeze cleared.
How long is the growing season in Marietta-Alderwood?
Measured between 28°F hard freezes, Marietta-Alderwood sees about 131 frost-free days — roughly May 29 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 19 to Sep 23, about 96 days.
Is the soil safe to grow vegetables in Marietta-Alderwood?
The federal record around Marietta-Alderwood is a meaningful one — 774 documented sites, mostly Underground Storage Tanks entries (334), the nearest Underground Storage Tanks record about 0.4 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 gardeners stretch the season in Marietta-Alderwood?
With about 131 frost-free days between hard freezes, Marietta-Alderwood rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 159 to 187 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 29 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Marietta-Alderwood's scale — its 8b band and its 131-day season. Your yard writes its own version of Marietta-Alderwood'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 Marietta-Alderwood’s own scale
4 of the readings below were taken at Marietta-Alderwood's own scale — the 3,722 acres it covers and 774 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Marietta-Alderwood's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 774 documented contamination sites on the federal record near Marietta-Alderwood, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Marietta-Alderwood's boundary and the 3,722 acres inside itUS Census TIGER/Line 2025
- Marietta-Alderwood sits in the Puget Lowland — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Marietta-Alderwood has no normal of its own, so its county's is the closest measured readfrom Whatcom County
- Soil character — no town-scale survey exists, so Marietta-Alderwood's 3,722 acres read through its county's SSURGO summaryfrom Whatcom 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 Whatcom 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 Whatcom County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Marietta-Alderwood's 3,722 acreswhy one lot differs from the next →
- Which side of Marietta-Alderwood you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,722 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 Marietta-Alderwood-wide figureread your own land →
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