Platinum, Alaska, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include cabbage, cranberry, cilantro, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Platinum, 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 Platinum 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 Platinum — soil, climate, flood, and parcel records. How we handle your address.
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Platinum — the short answer
Platinum, Alaska: USDA zone 4b, about 142 days between hard freezes, across 30K acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 10
- Bethel Census Area normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Sep 29
- Bethel Census Area normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~142
- Bethel Census Area normal — NOAA 1991–2020, nearest to this town
- City area
- 30K 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 Bethel Census Area’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 4b is Platinum's average, not your lot's — a low corner or a tree line moves it. Against Platinum's 142-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Platinum
Each reading below is measured for Platinum itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsPlatinum runs about 142 days between hard freezes (read from Bethel Census Area, the closest normal to Platinum) — 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
MeasuredPlatinum sits in USDA hardiness zone 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 Platinum
Every plant below cleared Platinum's own zone 4b and its 142-day season. Each card opens that plant's Alaska profile. How we score.
Is it too late to plant in Platinum?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 29 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What's on the federal record near Platinum
Closest first, within ~10 miles of Platinum. Listing isn't leaking, and distance isn't exposure.
- Red MountainMining · 2100 ft
- Clara Creek Platinum-Gold Placer MineMining · 1.2 mi
- Clara CreekMining · 1.3 mi
- Squirrel CreekMining · 1.4 mi
- Dowry Creek Platinum PlacerMining · 1.5 mi
- Boulder CreekMining · 1.5 mi
- Last Chance CreekMining · 1.5 mi
- Salmon River BenchMining · 1.8 mi
- Platinum CreekMining · 2.0 mi
- Squirrel Creek Platinum PlacerMining · 2.1 mi
- Dry Gulch Platinum PlacerMining · 2.1 mi
- Fox Gulch Platinum PlacerMining · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Platinum'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 Platinum.
Severity Distribution
within ~10 miles of Platinum
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Platinum, Mining runs higher than the national average — 40 sites within ~10 miles of Platinum. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Platinum
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 Platinum average
Your land is one point inside Platinum
Everything above resolves to Platinum as a whole — one PHZM band, read across 30K acres, with hard-freeze dates borrowed from Bethel Census Area’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 Platinum Average
Platinum Average
- ●USDA Zones 4b, averaged across Platinum
- ●One soil character for all of Platinum
- ●Frost dates read at Platinum's scale: May 10 to Sep 29
YOUR Parcel
- ✓Your exact zone, not Platinum's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Platinum
Pull a site-specific report for your exact address in Platinum, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Platinum averages can't show:
We read public map data around Platinum — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Platinum average
How we know this about Platinum
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 Bethel Census Area’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 Platinum
When does frost risk typically end in Platinum?
The last hard freeze (28°F) in Platinum typically lands around May 10, 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 31.
When is the first frost in Platinum?
The first hard freeze (28°F) in Platinum typically arrives around Sep 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 15, so the watching starts about Aug 30 — about 142 days after the spring freeze cleared.
How long is the growing season in Platinum?
Measured between 28°F hard freezes, Platinum sees about 142 frost-free days — roughly May 10 through Sep 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 31 to Sep 15, about 107 days.
Is the soil safe to grow vegetables in Platinum?
The federal record around Platinum is a meaningful one — 40 documented sites, mostly Mining entries (40), the nearest Mining 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 Platinum?
With about 142 frost-free days between hard freezes, Platinum 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 170 to 198 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 10 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Platinum's scale — its 4b band and its 142-day season. Your yard writes its own version of Platinum'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 Platinum’s own scale
4 of the readings below were taken at Platinum's own scale — the 30,250 acres it covers and 40 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Platinum's own USDA hardiness band, zones 4bUSDA PHZM 2023
- 40 documented contamination sites on the federal record near Platinum, the closest Mining record about 0.4 miles out from the town centreFederal environmental registers
- Platinum's boundary and the 30,250 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~142-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The 28°F hard-freeze dates — Platinum has no normal of its own, so its county's is the closest measured readfrom Bethel Census Area
- Soil character — no town-scale survey exists, so Platinum's 30,250 acres read through its county's SSURGO summaryfrom Bethel County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Bethel 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 Bethel County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Platinum's 30,250 acreswhy one lot differs from the next →
- Which side of Platinum you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 30,250 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining 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 Platinum-wide figureread your own land →
More in Alaska
Wider growing context
What grows across AlaskaPlatinum sits outside our named growing regions, so Alaska as a whole is its closest context here.
Nearby growing guides