Susitna, Alaska, sits in USDA hardiness zone 4a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, cranberry, cilantro, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Susitna, 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 Susitna 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 Susitna — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Susitna — the short answer
Susitna, Alaska: USDA zone 4a, about 145 days between hard freezes, across 138K acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 6
- Matanuska-Susitna Borough normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Sep 28
- Matanuska-Susitna Borough normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~145
- Matanuska-Susitna Borough normal — NOAA 1991–2020, nearest to this town
- Town area
- 138K 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 Matanuska-Susitna Borough’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 4a is Susitna's average, not your lot's — a low corner or a tree line moves it. Against Susitna's 145-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Susitna
Each reading below is measured for Susitna itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSusitna runs about 145 days between hard freezes (read from Matanuska-Susitna Borough, the closest normal to Susitna) — 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
MeasuredSusitna sits in USDA hardiness zone 4a.
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 Susitna
Every plant below cleared Susitna's own zone 4a and its 145-day season. Each card opens that plant's Alaska profile. How we score.
Is it too late to plant in Susitna?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 28 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
Environmental Check
No contamination sources found near Susitna
We checked 9 federal environmental databases and found no recorded contamination sites in this area. A clean starting point for growing.
Your land is one point inside Susitna
Everything above resolves to Susitna as a whole — one PHZM band, read across 138K acres, with hard-freeze dates borrowed from Matanuska-Susitna Borough’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 Susitna Average
Susitna Average
- ●USDA Zones 4a, averaged across Susitna
- ●One soil character for all of Susitna
- ●Frost dates read at Susitna's scale: May 6 to Sep 28
YOUR Parcel
- ✓Your exact zone, not Susitna's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Susitna
Pull a site-specific report for your exact address in Susitna, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Susitna averages can't show:
We read public map data around Susitna — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Susitna average
How we know this about Susitna
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 Matanuska-Susitna 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 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 Susitna
When does frost risk typically end in Susitna?
The last hard freeze (28°F) in Susitna typically lands around May 6, 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 27.
When is the first frost in Susitna?
The first hard freeze (28°F) in Susitna typically arrives around Sep 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 14, so the watching starts about Aug 29 — about 145 days after the spring freeze cleared.
How long is the growing season in Susitna?
Measured between 28°F hard freezes, Susitna sees about 145 frost-free days — roughly May 6 through Sep 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 27 to Sep 14, about 110 days.
Is the soil safe to grow vegetables in Susitna?
No database can certify soil, but the federal record here is clean: we checked all 9 federal contamination source types and found no documented sites within the search radii around Susitna. That means nothing is on record — not that the land is certified clean — so a one-time soil test is still the way to know your own yard's history.
How do gardeners stretch the season in Susitna?
With about 145 frost-free days between hard freezes, Susitna 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 173 to 201 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 6 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Susitna's scale — its 4a band and its 145-day season. Your yard writes its own version of Susitna'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 Susitna’s own scale
3 of the readings below were taken at Susitna's own scale — the 138,253 acres it covers; 5 are borrowed from a wider read, named and linked below.
Measured here
- Susitna's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Susitna's boundary and the 138,253 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~145-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The 28°F hard-freeze dates — Susitna has no normal of its own, so its county's is the closest measured readfrom Matanuska-Susitna Borough
- Soil character — no town-scale survey exists, so Susitna's 138,253 acres read through its county's SSURGO summaryfrom Matanuska-Susitna County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Matanuska-Susitna 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 Matanuska-Susitna County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Susitna's 138,253 acreswhy one lot differs from the next →
- Which side of Susitna you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 138,253 acresreading your own microclimate →
- How much sun your beds actually get once the trees leaf outmeasuring sun honestly →
- 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 Susitna-wide figureread your own land →
More in Alaska
Wider growing context
What grows across AlaskaSusitna sits outside our named growing regions, so Alaska as a whole is its closest context here.
Nearby growing guides