Sitka County, 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.
Reliable performers under these conditions include cabbage, potato, rhubarb, and kale; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring
Sitka County holds more than one microclimate.
Soils and elevations shift across Sitka County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Quick Facts
USDA Zones
3a-4b
Last Frost (state avg.)
May 1 - Jun 15
First Frost (state avg.)
Aug 15 - Oct 1
County Area
1.8M acres
Hardiness Zone Range
Growing Season
Zone maps are averages across Sitka County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Sitka County
Detailed USDA soil-survey (SSURGO) mapping is limited across Sitka 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 Grows in Sitka County
Plants matched to Sitka County's USDA zones 3a-4b — each links to its full growing profile.
Growing Challenges in Alaska
What an experienced grower plans around here — each one has a move.
Extremely short growing season (70-110 frost-free days)
A high tunnel or greenhouse is standard Alaska practice — it turns 90 outdoor days into a real growing season.
Permafrost prevents deep root growth in many areas
Raised beds lift roots above the cold and warm weeks earlier in spring — the proven northern workaround.
Limited soil development in glacial terrain
Start with a soil test to see what glacial ground actually has, then build up with imported topsoil and steady compost.
For cultivar selection, pest pressure, and planting-time guidance specific to Alaska, the UAF Cooperative Extension Service is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Sitka County — and how to grow with it.
We checked the federal record across Sitka County — 179 documented sites across 6 of the 9 source types we track.
The most significant on record: 6 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Sitka County 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.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
across Sitka County
Severity Distribution
across Sitka County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sitka County, two things run higher than the national average — Mining (88 sites) and Superfund (6 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 Sitka County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Sitka County Average
- ●USDA Zones 3a-4b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Sitka County
Pull a site-specific report for your exact address in Sitka County, Alaska — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Sitka County, Alaska
- USDA Hardiness Zones: 3a-4b (USDA PHZM 2023)
- Last Spring Frost (state avg.): May 1 - Jun 15 (NOAA 30-Year Climate Normals)
- First Fall Frost (state avg.): Aug 15 - Oct 1 (NOAA 30-Year Climate Normals)
- County Land Area: 1.8M acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Sitka County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Sitka County, Alaska?
Sitka County sits in USDA hardiness zones 3a-4b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Sitka County?
Sitka County follows Alaska's statewide frost window: last spring frost around May 1 - Jun 15 and first fall frost around Aug 15 - Oct 1, per NOAA 30-year climate normals (1991–2020). Frost dates shift with elevation and local microclimate, so watch your own site's cold pockets.
What vegetables grow in Sitka County?
Sitka County's zones 3a-4b support a wide range — strong performers include Cabbage, Potato, Rhubarb, and Kale. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Sitka County, really?
Officially, Sitka County sits in USDA zones 3a-4b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Sitka County?
The federal record around Sitka County runs heavier than most — 179 documented sites — 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.
Just moved to Sitka County — what should I know before planting?
Start with three facts. Sitka County sits in USDA zones 3a-4b, which sets what survives winter; the statewide frost window runs about May 1 - Jun 15 to Aug 15 - Oct 1 (NOAA 30-year climate normals); and 179 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Sitka County average. Your yard writes its own version — 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.