South Lakes, Alaska, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in South Lakes, 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 South Lakes 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 South Lakes — soil, climate, flood, and parcel records. How we handle your address.
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South Lakes — the short answer
South Lakes, Alaska: USDA zone 5a, about 145 days between hard freezes, across 5K acres of town.
- USDA zone
- 5a
- 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
- 5K 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 5a is South Lakes's average, not your lot's — a low corner or a tree line moves it. Against South Lakes's 145-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Lakes
Each reading below is measured for South Lakes itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSouth Lakes runs about 145 days between hard freezes (read from Matanuska-Susitna Borough, the closest normal to South Lakes) — 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
MeasuredSouth Lakes sits in USDA hardiness zone 5a.
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 South Lakes
Every plant below cleared South Lakes's own zone 5a and its 145-day season. Each card opens that plant's Alaska profile. How we score.
Is it too late to plant in South Lakes?
Almost never — the real question is what to plant next. 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.
What's on the federal record near South Lakes
Closest first, within ~10 miles of South Lakes. Listing isn't leaking, and distance isn't exposure.
- PRO-WEST IIBrownfields · 950 ft
- SA01700108BAAB1 001Nitrate · 1300 ft
- SA01700105CAAA1 031Nitrate · 1700 ft
- SA01700104CCCC1 001Nitrate · 0.6 mi
- SA01700106ACAA1 007Nitrate · 0.9 mi
- SA01800132CDAC2 001Nitrate · 1.0 mi
- JOHNSON TIREBrownfields · 1.2 mi
- ENSTAR NATURAL GASBrownfields · 1.2 mi
- Alpac Corporation FacilityUnderground Storage Tanks · 1.3 mi
- Valley MotorsUnderground Storage Tanks · 1.3 mi
- Fairview Marketplace - Wasilla ShellUnderground Storage Tanks · 1.3 mi
- SA01700106CCDC1 001Nitrate · 1.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from South Lakes'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 South Lakes.
Total Sites
416
within ~10 miles of South Lakes
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of South Lakes
Severity Distribution
within ~10 miles of South Lakes
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around South Lakes, Nitrate runs higher than the national average — 226 sites within ~10 miles of South Lakes. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 South Lakes
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 South Lakes average
Your land is one point inside South Lakes
Everything above resolves to South Lakes as a whole — one PHZM band, read across 5K 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 South Lakes Average
South Lakes Average
- ●USDA Zones 5a, averaged across South Lakes
- ●One soil character for all of South Lakes
- ●Frost dates read at South Lakes's scale: May 6 to Sep 28
YOUR Parcel
- ✓Your exact zone, not South Lakes's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Lakes
Pull a site-specific report for your exact address in South Lakes, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Lakes averages can't show:
We read public map data around South Lakes — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Lakes average
How we know this about South Lakes
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 South Lakes
When does frost risk typically end in South Lakes?
The last hard freeze (28°F) in South Lakes 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 South Lakes?
The first hard freeze (28°F) in South Lakes 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 South Lakes?
Measured between 28°F hard freezes, South Lakes 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 South Lakes?
The federal record around South Lakes is a meaningful one — 416 documented sites, mostly Nitrate entries (226), the nearest Brownfields record about 0.2 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 South Lakes?
With about 145 frost-free days between hard freezes, South Lakes 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 South Lakes's scale — its 5a band and its 145-day season. Your yard writes its own version of South Lakes'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 South Lakes’s own scale
4 of the readings below were taken at South Lakes's own scale — the 4,993 acres it covers and 416 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- South Lakes's own USDA hardiness band, zones 5aUSDA PHZM 2023
- 416 documented contamination sites on the federal record near South Lakes, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- South Lakes's boundary and the 4,993 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~145-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The 28°F hard-freeze dates — South Lakes 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 South Lakes's 4,993 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 South Lakes's 4,993 acreswhy one lot differs from the next →
- Which side of South Lakes you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,993 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 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 South Lakes-wide figureread your own land →
More in Alaska
Wider growing context
What grows across AlaskaSouth Lakes sits outside our named growing regions, so Alaska as a whole is its closest context here.
Nearby growing guides