Kupreanof, Alaska, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cabbage, pawpaw, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Kupreanof, 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 Kupreanof 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 Kupreanof — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Kupreanof — the short answer
Kupreanof, Alaska: USDA zone 7a, about 196 days between hard freezes, across 2K acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 16
- Petersburg Borough normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Oct 29
- Petersburg Borough normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~196
- Petersburg Borough normal — NOAA 1991–2020, nearest to this town
- City area
- 2K 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 Petersburg Borough’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 7a is Kupreanof's average, not your lot's — a low corner or a tree line moves it. Against Kupreanof's 196-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Kupreanof
Each reading below is measured for Kupreanof itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsKupreanof runs about 196 days between hard freezes (read from Petersburg Borough, the closest normal to Kupreanof) — 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
MeasuredKupreanof sits in USDA hardiness zone 7a.
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
What Grows in Kupreanof
Every plant below cleared Kupreanof's own zone 7a and its 196-day season. Each card opens that plant's Alaska profile. How we score.
Is it too late to plant in Kupreanof?
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 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Kupreanof
Closest first, within ~10 miles of Kupreanof. Listing isn't leaking, and distance isn't exposure.
- ICICLE SEAFOODS PETERSBURG PROCESSINGBrownfields · 0.7 mi
- Icicle Seafoods, Inc.Underground Storage Tanks · 0.7 mi
- TRIDENT SEAFOODS PETERSBURG CANNERYToxics Release Inventory · 0.8 mi
- Municipal Building Parking LotUnderground Storage Tanks · 0.9 mi
- PETERSBURG CY OFBrownfields · 0.9 mi
- Southeast Island FuelUnderground Storage Tanks · 0.9 mi
- USDOT CG CUTTER PETERSBURG MOORINGSBrownfields · 0.9 mi
- TONKA SEAFOODSBrownfields · 0.9 mi
- Petersburg Motors, Inc.Underground Storage Tanks · 1.0 mi
- PETERSBURG MOTORS INCBrownfields · 1.0 mi
- ALASKA FUEL SERVICE (UNOCAL)Brownfields · 1.0 mi
- PETRO MARINE SERVICES - PETERSBURGBrownfields · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kupreanof'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 Kupreanof.
Total Sites
34
within ~10 miles of Kupreanof
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Kupreanof
Severity Distribution
within ~10 miles of Kupreanof
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Kupreanof, Superfund runs higher than the national average — 4 sites within ~10 miles of Kupreanof. That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Kupreanof
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 Kupreanof average
Your land is one point inside Kupreanof
Everything above resolves to Kupreanof as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Petersburg Borough’s record because no 30-year normal resolves at this city’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 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 Kupreanof Average
Kupreanof Average
- ●USDA Zones 7a, averaged across Kupreanof
- ●One soil character for all of Kupreanof
- ●Frost dates read at Kupreanof's scale: Apr 16 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Kupreanof's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Kupreanof
Pull a site-specific report for your exact address in Kupreanof, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kupreanof averages can't show:
We read public map data around Kupreanof — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kupreanof average
How we know this about Kupreanof
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 Petersburg Borough’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 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 Kupreanof
When does frost risk typically end in Kupreanof?
The last hard freeze (28°F) in Kupreanof typically lands around Apr 16, 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 7.
When is the first frost in Kupreanof?
The first hard freeze (28°F) in Kupreanof typically arrives around Oct 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 15, so the watching starts about Sep 29 — about 196 days after the spring freeze cleared.
How long is the growing season in Kupreanof?
Measured between 28°F hard freezes, Kupreanof sees about 196 frost-free days — roughly Apr 16 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 7 to Oct 15, about 161 days.
Is the soil safe to grow vegetables in Kupreanof?
The federal record around Kupreanof is a meaningful one — 34 documented sites, mostly Underground Storage Tanks entries (15), the nearest Brownfields record about 0.7 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 Kupreanof?
From about Sep 29 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 29 (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 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Kupreanof's scale — its 7a band and its 196-day season. Your yard writes its own version of Kupreanof'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 Kupreanof’s own scale
4 of the readings below were taken at Kupreanof's own scale — the 1,933 acres it covers and 34 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Kupreanof's own USDA hardiness band, zones 7aUSDA PHZM 2023
- 34 documented contamination sites on the federal record near Kupreanof, the closest Brownfields record about 0.7 miles out from the town centreFederal environmental registers
- Kupreanof's boundary and the 1,933 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~196-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The 28°F hard-freeze dates — Kupreanof has no normal of its own, so its county's is the closest measured readfrom Petersburg Borough
- Soil character — no town-scale survey exists, so Kupreanof's 1,933 acres read through its county's SSURGO summaryfrom Petersburg County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Petersburg County
- The growing challenges every Alaska grower plans around — written at state scale, so they stay on the state guidefrom Alaska
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Petersburg County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Kupreanof's 1,933 acreswhy one lot differs from the next →
- Which side of Kupreanof you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,933 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.7 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 Kupreanof-wide figureread your own land →