Spirit Lake, Idaho, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Spirit 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 Spirit 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 Spirit Lake — soil, climate, flood, and parcel records. How we handle your address.
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Spirit Lake — the short answer
Spirit Lake, Idaho: USDA zone 6a, about 175 days between hard freezes, across 2K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~175
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City 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 6a is Spirit Lake's average, not your lot's — a low corner or a tree line moves it. Against Spirit Lake's 175-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Spirit Lake
Each reading below is measured for Spirit Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSpirit Lake runs about 175 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSpirit Lake sits in USDA hardiness zone 6a.
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 Spirit Lake is in
Spirit Lake sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Spirit Lake's own centroid rather than borrowed from Kootenai County.
What Grows in Spirit Lake
Every plant below cleared Spirit Lake's own zone 6a and its 175-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Spirit Lake?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 15 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Spirit Lake
Closest first, within ~10 miles of Spirit Lake. Listing isn't leaking, and distance isn't exposure.
- SPIRITS MINI STOPUnderground Storage Tanks · 650 ft
- MILLER'S FOOD CITY, INC.Underground Storage Tanks · 700 ft
- SPIRIT LAKE CTRL OFC (1360-BO1)Underground Storage Tanks · 750 ft
- IDAHO TRANSPORTATION DEPTUnderground Storage Tanks · 750 ft
- SPIRIT LAKE SERVICEUnderground Storage Tanks · 750 ft
- CITY MAINTENANCEUnderground Storage Tanks · 1000 ft
- LAKE HAVEN RESORT & MARINAUnderground Storage Tanks · 2100 ft
- 53N 04W 05DCD1Nitrate · 0.5 mi
- SEDLMAYER'S RESORTUnderground Storage Tanks · 0.8 mi
- Spirit Lake HICOUnderground Storage Tanks · 2.5 mi
- 54N 04W 29ABC1Nitrate · 2.7 mi
- 54N 05W 25BAD1Nitrate · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Spirit 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 Spirit Lake.
Total Sites
70
within ~10 miles of Spirit Lake
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Spirit Lake
Severity Distribution
within ~10 miles of Spirit Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Spirit Lake, Nitrate runs higher than the national average — 34 sites within ~10 miles of Spirit Lake. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Spirit 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 Spirit Lake average
Your land is one point inside Spirit Lake
Everything above resolves to Spirit Lake 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 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 Spirit Lake Average
Spirit Lake Average
- ●USDA Zones 6a, averaged across Spirit Lake
- ●One soil character for all of Spirit Lake
- ●Frost dates read at Spirit Lake's scale: Apr 23 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Spirit Lake's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Spirit Lake
Pull a site-specific report for your exact address in Spirit Lake, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Spirit Lake averages can't show:
We read public map data around Spirit Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Spirit Lake average
How we know this about Spirit Lake
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 Spirit Lake’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 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 Spirit Lake
When does frost risk typically end in Spirit Lake?
The last hard freeze (28°F) in Spirit Lake typically lands around Apr 23, 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 14.
When is the first frost in Spirit Lake?
The first hard freeze (28°F) in Spirit Lake typically arrives around Oct 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 1, so the watching starts about Sep 15 — about 175 days after the spring freeze cleared.
How long is the growing season in Spirit Lake?
Measured between 28°F hard freezes, Spirit Lake sees about 175 frost-free days — roughly Apr 23 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 14 to Oct 1, about 140 days.
Is the soil safe to grow vegetables in Spirit Lake?
The federal record around Spirit Lake shows 70 documented sites, mostly Nitrate entries (34), the nearest Underground Storage Tanks record about 0.1 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Spirit Lake?
From about Sep 15 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 Oct 15 (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 Oct 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Spirit Lake's scale — its 6a band and its 175-day season. Your yard writes its own version of Spirit 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 Spirit Lake’s own scale
6 of the readings below were taken at Spirit Lake's own scale — its own ~175-day season between 28°F freezes, the 1,572 acres it covers and 70 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Spirit Lake's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Spirit Lake's own 28°F hard-freeze dates, about Apr 23 and Oct 15 and the ~175-day span between themNOAA 1991–2020 Climate Normals
- 70 documented contamination sites on the federal record near Spirit Lake, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Spirit Lake's boundary and the 1,572 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~175-day seasonGrowable Ground crop-matching engine
- The ecoregion at Spirit Lake's own centroid, the Northern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Spirit Lake's 1,572 acres read through its county's SSURGO summaryfrom Kootenai County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kootenai County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Kootenai County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Spirit Lake's 1,572 acreswhy one lot differs from the next →
- Which side of Spirit 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 1,572 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Spirit Lake-wide figureread your own land →
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