Martha Lake, Washington, sits in USDA hardiness zone 9a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
A short list that earns its place here — kale, potato, garlic, and western red cedar — with any one site's soil, sun, and drainage making the final cut.
Even in Martha Lake, 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 Martha Lake 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 Martha Lake — soil, climate, flood, and parcel records. How we handle your address.
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Martha Lake — the short answer
Martha Lake, Washington: USDA zone 9a, about 208 days between hard freezes, across 3K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- Snohomish County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 9
- Snohomish County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~208
- Snohomish County normal — NOAA 1991–2020, nearest to this town
- Town area
- 3K 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 Snohomish County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Martha Lake's average, not your lot's — a low corner or a tree line moves it. Against Martha Lake's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Martha Lake
Each reading below is measured for Martha Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMartha Lake runs about 208 days between hard freezes (read from Snohomish County, the closest normal to Martha Lake) — 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
MeasuredMartha Lake 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 Martha Lake is in
Martha Lake sits in the Puget Lowland — EPA Level III, inside the wider Marine West Coast Forest. That is read at Martha Lake's own centroid, and it is not what its county reads: Snohomish County is mostly North Cascades. The wider page above you is answering a different question about different ground.
What Grows in Martha Lake
Plants matched to Martha Lake'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 Martha Lake?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 9 — 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 Martha Lake
Closest first, within ~10 miles of Martha Lake. Listing isn't leaking, and distance isn't exposure.
- SHERWIN WILLIAMS STORE 703559Brownfields · 1600 ft
- MY GOODS MARKET #5091Underground Storage Tanks · 1800 ft
- FIRESTONE 31K7Underground Storage Tanks · 2300 ft
- GAI'S SEATTLE FRENCH BAKING COMPANYUnderground Storage Tanks · 2400 ft
- I.S.N. GROCERYUnderground Storage Tanks · 2600 ft
- QSMC INC 1064Underground Storage Tanks · 0.5 mi
- GREASE MONKEY 473Underground Storage Tanks · 0.6 mi
- PLAID PANTRY 305Underground Storage Tanks · 0.6 mi
- MY GOODS MARKET #5500Underground Storage Tanks · 0.7 mi
- WALGREENS 6302Brownfields · 0.7 mi
- QFC MILL CREEKBrownfields · 0.7 mi
- AVS GAS & GROCERIESUnderground Storage Tanks · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Martha Lake'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 Martha Lake.
Total Sites
1,840
within ~10 miles of Martha Lake
Risk Level
Elevated
Highest-severity
5 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Martha Lake
Severity Distribution
within ~10 miles of Martha Lake
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.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Martha Lake
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 Martha Lake average
Your land is one point inside Martha Lake
Everything above resolves to Martha Lake as a whole — one PHZM band, read across 3K acres, with hard-freeze dates borrowed from Snohomish 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 Martha Lake Average
Martha Lake Average
- ●USDA Zones 9a, averaged across Martha Lake
- ●One soil character for all of Martha Lake
- ●Frost dates read at Martha Lake's scale: Apr 15 to Nov 9
YOUR Parcel
- ✓Your exact zone, not Martha Lake's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Martha Lake
Pull a site-specific report for your exact address in Martha Lake, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Martha Lake averages can't show:
We read public map data around Martha Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Martha Lake average
How we know this about Martha Lake
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 Snohomish 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 Martha Lake
When does frost risk typically end in Martha Lake?
The last hard freeze (28°F) in Martha Lake typically lands around Apr 15, 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 May 6.
When is the first frost in Martha Lake?
The first hard freeze (28°F) in Martha Lake typically arrives around Nov 9, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 26, so the watching starts about Oct 10 — about 208 days after the spring freeze cleared.
How long is the growing season in Martha Lake?
Measured between 28°F hard freezes, Martha Lake sees about 208 frost-free days — roughly Apr 15 through Nov 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 26, about 173 days.
Is the soil safe to grow vegetables in Martha Lake?
The federal record around Martha Lake is a meaningful one — 1,840 documented sites, mostly Underground Storage Tanks entries (1,112), the nearest Brownfields record about 0.3 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 Martha Lake?
From about Oct 10 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 9 (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 9. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Martha Lake's scale — its 9a band and its 208-day season. Your yard writes its own version of Martha Lake'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 Martha Lake’s own scale
4 of the readings below were taken at Martha Lake's own scale — the 2,914 acres it covers and 1,840 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Martha Lake's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 1,840 documented contamination sites on the federal record near Martha Lake, the closest Brownfields record about 0.3 miles out from the town centreFederal environmental registers
- Martha Lake's boundary and the 2,914 acres inside itUS Census TIGER/Line 2025
- Martha Lake 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 — Martha Lake has no normal of its own, so its county's is the closest measured readfrom Snohomish County
- Soil character — no town-scale survey exists, so Martha Lake's 2,914 acres read through its county's SSURGO summaryfrom Snohomish 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 Snohomish 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 Snohomish County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Martha Lake's 2,914 acreswhy one lot differs from the next →
- Which side of Martha Lake you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,914 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.3 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 Martha Lake-wide figureread your own land →