Copper River Census Area, in Alaska, sits in USDA hardiness zones 3a-4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Growers here do well with cabbage, cranberry, epazote, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Copper River Census Area holds more than one microclimate.
Soils and elevations shift across Copper River Census Area, so your frost dates and drainage aren't the county average. 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 Copper River Census Area — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Copper River Census Area — the short answer
Copper River Census Area, Alaska: USDA zones 3a-4b, about 109 days between hard freezes, across 15.8M acres.
- USDA zones
- 3a-4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 21
- NABESNA station, 2,920 ft — 63 km away, 21 yr record
- First hard freeze (28°F)
- Sep 7
- NABESNA station, 2,920 ft — 63 km away, 21 yr record
- Days between freezes
- ~109
- NABESNA station, 2,920 ft — 63 km away, 21 yr record
- County area
- 15.8M acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 3a-4b is Copper River Census Area's average, not your lot's — a low corner or a tree line moves it. Against Copper River Census Area's 109-day season, see what your own ground reads.
Soil in Copper River County
Detailed USDA soil-survey (SSURGO) mapping is limited across Copper River County, so there isn't a reliable county-wide soil summary to show here yet — a gap in the national survey, not in the ground itself.
Soil still varies lot by lot — soil types explained.
What this means for growing in Copper River Census Area
Each reading below is measured for Copper River Census Area itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCopper River Census Area runs about 109 days between hard freezes — 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
MeasuredCopper River Census Area sits in USDA hardiness zones 3a-4b.
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 Copper River Census Area
We scored all 1,086 plants against Copper River Census Area's own USDA zone 3a-4b and its own 109-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Alaska profile.
Is it too late to plant in Copper River Census Area?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 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.
Safe to Grow Here?
What the federal record shows across Copper River County — and how to grow with it.
We checked the federal record across Copper River County — 607 documented sites across 5 of the 9 source types we track.
The most significant on record: 9 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Copper River Census Area carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Copper River Census Area
Closest first, across Copper River County. Listing isn't leaking, and distance isn't exposure.
- Hidden TreasureMining · 16.1 mi
- Homestake and New HomeMining · 16.6 mi
- Fall CreekMining · 16.6 mi
- Chitty LodeMining · 17.3 mi
- Good EnoughMining · 18.1 mi
- Unnamed (on Mineral Creek)Mining · 19.4 mi
- Mineral CreekMining · 19.4 mi
- Unnamed (southwest flank of Granite Peak)Mining · 20.2 mi
- Silver StarMining · 20.4 mi
- Alaska Kotsina Copper Co.Mining · 20.5 mi
- Surprise CreekMining · 20.5 mi
- Lost CabinMining · 20.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Copper River Census Area'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 Copper River Census Area.
Total Sites
607
across Copper River County
Risk Level
High
Highest-severity
9 Superfund sites (none NPL-listed)
Sources Checked
across Copper River County
Severity Distribution
across Copper River County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Copper River Census Area, two things run higher than the national average across Copper River County — Mining (420 sites) and Superfund (9 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Copper River Census Area
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 Copper River Census Area average
Your land is one point inside Copper River Census Area
Everything above resolves to Copper River Census Area as a whole — one PHZM band and one county frost record, read across 15.8M 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 county 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 county average.
Your Lot vs the Copper River Census Area Average
Copper River Census Area Average
- ●USDA Zones 3a-4b, averaged across Copper River Census Area
- ●One soil character for all of Copper River Census Area
- ●Frost dates read at Copper River Census Area's scale: May 21 to Sep 7
YOUR Parcel
- ✓Your exact zone, not Copper River Census Area's 3a-4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Copper River Census Area
Pull a site-specific report for your exact address in Copper River Census Area, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Copper River Census Area averages can't show:
We read public map data around Copper River Census Area — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Copper River Census Area average
How we know this about Copper River Census Area
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Copper River Census Area carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Copper River Census Area
When does frost risk typically end in Copper River Census Area?
The last hard freeze (28°F) in Copper River Census Area typically lands around May 21, 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 11.
How long is the growing season in Copper River Census Area?
Measured between 28°F hard freezes, Copper River Census Area sees about 109 frost-free days — roughly May 21 through Sep 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 11 to Aug 24, about 74 days.
Is the soil safe to grow vegetables in Copper River Census Area?
The federal record around Copper River Census Area runs heavier than most — 607 documented sites, mostly Mining entries (420), the nearest Mining record about 16 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do gardeners stretch the season in Copper River Census Area?
With about 109 frost-free days between hard freezes, Copper River Census Area 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 137 to 165 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 21 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Copper River Census Area's scale — its 3a-4b band and its 109-day season. Your yard writes its own version of Copper River Census Area's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Alaska's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Copper River Census Area’s own scale
5 of the readings below were taken at Copper River Census Area's own scale — its own ~109-day span between 28°F freezes and 607 documented sites inside its boundary; 2 are borrowed from a wider read, named and linked below.
Measured here
- Copper River Census Area's own USDA hardiness band, zones 3a-4bUSDA PHZM 2023
- Copper River Census Area's own 28°F hard-freeze dates and its ~109-day span between themNOAA 1991–2020 Climate Normals
- 607 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 16 miles outFederal environmental registers
- Copper River Census Area's boundary and the 15,774,294 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3a-4b and a ~109-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
What this page can’t tell you
- How the season shifts across Copper River Census Area — the ~109 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Copper River Census Area's 15,774,294 acreswhy one lot differs from the next →
- Which of those 607 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Copper River Census Arearead your own land →