Ketchikan Gateway Borough, in Alaska, sits in USDA hardiness zones 3a-4b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Crops well matched to these conditions include cabbage, cranberry, turkish rocket, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Ketchikan Gateway Borough lies within the Southeast Alaska / Inside Passage Panhandle — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Ketchikan Gateway Borough holds more than one microclimate.
Soils and elevations shift across Ketchikan Gateway Borough, 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 Ketchikan Gateway Borough — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Ketchikan Gateway Borough — the short answer
Ketchikan Gateway Borough, Alaska: USDA zones 3a-4b, about 223 days between hard freezes, across 3.1M acres.
- USDA zones
- 3a-4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- KETCHIKAN AIRPORT station, 84 ft — 40 km away, 30 yr record
- First hard freeze (28°F)
- Nov 10
- KETCHIKAN AIRPORT station, 84 ft — 40 km away, 30 yr record
- Days between freezes
- ~223
- KETCHIKAN AIRPORT station, 84 ft — 40 km away, 30 yr record
- County area
- 3.1M 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 Ketchikan Gateway Borough's average, not your lot's — a low corner or a tree line moves it. Against Ketchikan Gateway Borough's 223-day season, see what your own ground reads.
Soil in Ketchikan Gateway County
Across Ketchikan Gateway County, the ground is predominantly Spodosols, where McGilvery, Kina, and Tolstoi are the most extensive named soil series. The soil is generally very poorly drained with a silt loam surface. Topsoil pH runs about 4.0–4.5, extremely acidic. Rainfall drains through hydrologic group D soils.
Soil order
Spodosols
Drainage
Very poorly drained
Hydric soils
51%
Soil still varies lot by lot — soil types explained.
How the ground varies across Ketchikan Gateway Borough
The USDA soil survey maps 26% of Ketchikan Gateway Borough as very poorly drained — but another 46% drains differently: 22% well drained, 14% poorly drained.
McGilvery is the most extensive named soil at 12% of mapped acres, then Kina (9%) and Tolstoi (8%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Ketchikan Gateway Borough
Each reading below is measured for Ketchikan Gateway Borough itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Ketchikan Gateway Borough are very poorly drained, in hydrologic group D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Ketchikan Gateway Borough runs about pH 4.0–4.5, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredKetchikan Gateway Borough runs about 223 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredKetchikan Gateway Borough 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 Ketchikan Gateway Borough
We scored all 1,086 plants against Ketchikan Gateway Borough's own USDA zone 3a-4b and its own 223-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 Ketchikan Gateway Borough?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Safe to Grow Here?
What the federal record shows across Ketchikan Gateway County — and how to grow with it.
We checked the federal record across Ketchikan Gateway County — 281 documented sites across 6 of the 9 source types we track.
The most significant on record: 4 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Ketchikan Gateway Borough 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 Ketchikan Gateway Borough
Closest first, across Ketchikan Gateway County. Listing isn't leaking, and distance isn't exposure.
- LakeMining · 4.5 mi
- KeystoneMining · 4.7 mi
- MassachusettsMining · 5.0 mi
- TyeeMining · 5.1 mi
- Ella PointMining · 5.4 mi
- BalticMining · 5.7 mi
- Unnamed (near Ella Point)Mining · 5.8 mi
- Baltic StarMining · 5.8 mi
- Sea BreezeMining · 6.3 mi
- Gold BannerMining · 6.4 mi
- Goo GooMining · 6.4 mi
- High HorseMining · 6.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Ketchikan Gateway Borough'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 Ketchikan Gateway Borough.
Total Sites
281
across Ketchikan Gateway County
Risk Level
High
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
across Ketchikan Gateway County
Severity Distribution
across Ketchikan Gateway County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Ketchikan Gateway Borough, two things run higher than the national average across Ketchikan Gateway County — Mining (178 sites) and Superfund (4 sites). That's not a problem with your land — it's information about 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.
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 Ketchikan Gateway Borough
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 Ketchikan Gateway Borough average
Your land is one point inside Ketchikan Gateway Borough
Everything above resolves to Ketchikan Gateway Borough as a whole — one PHZM band and one county frost record, read across 3.1M 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 Ketchikan Gateway Borough Average
Ketchikan Gateway Borough Average
- ●USDA Zones 3a-4b, averaged across Ketchikan Gateway Borough
- ●One soil character for all of Ketchikan Gateway Borough
- ●Frost dates read at Ketchikan Gateway Borough's scale: Apr 1 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Ketchikan Gateway Borough's 3a-4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Ketchikan Gateway Borough
Pull a site-specific report for your exact address in Ketchikan Gateway Borough, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Ketchikan Gateway Borough averages can't show:
We read public map data around Ketchikan Gateway Borough — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ketchikan Gateway Borough average
How we know this about Ketchikan Gateway Borough
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 Ketchikan Gateway Borough carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Ketchikan Gateway Borough
When does frost risk typically end in Ketchikan Gateway Borough?
The last hard freeze (28°F) in Ketchikan Gateway Borough typically lands around Apr 1, 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 Apr 22.
How long is the growing season in Ketchikan Gateway Borough?
Measured between 28°F hard freezes, Ketchikan Gateway Borough sees about 223 frost-free days — roughly Apr 1 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Oct 27, about 188 days.
Is the soil safe to grow vegetables in Ketchikan Gateway Borough?
The federal record around Ketchikan Gateway Borough runs heavier than most — 281 documented sites, mostly Mining entries (178), the nearest Mining record about 4.5 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.
Everything above is measured at Ketchikan Gateway Borough's scale — its 3a-4b band and its 223-day season. Your yard writes its own version of Ketchikan Gateway Borough'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 Ketchikan Gateway Borough’s own scale
6 of the readings below were taken at Ketchikan Gateway Borough's own scale — its own ~223-day span between 28°F freezes, the 3 most extensive soil series mapped here and 281 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Ketchikan Gateway Borough's own USDA hardiness band, zones 3a-4bUSDA PHZM 2023
- Ketchikan Gateway Borough's own 28°F hard-freeze dates and its ~223-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Ketchikan Gateway BoroughUSDA NRCS SSURGO
- 281 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 4.5 miles outFederal environmental registers
- Ketchikan Gateway Borough's boundary and the 3,108,536 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3a-4b and a ~223-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The growing challenges every Alaska grower plans around — written at state scale, so they stay on the state guidefrom Alaska
What this page can’t tell you
- How the season shifts across Ketchikan Gateway Borough — the ~223 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 Ketchikan Gateway Borough's 3,108,536 acreswhy one lot differs from the next →
- Which of those 281 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 Ketchikan Gateway Boroughread your own land →