The Southeast Alaska / Inside Passage Panhandle spans USDA hardiness zones 5a-8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Alaska's temperate rainforest inverts the usual Alaska problem: the constraint here isn't cold, it's a lack of summer heat. The Inside Passage panhandle spans USDA zones 5a–8a overall — 7a–8a in the coastal towns where nearly all of its gardening happens (Sitka 8a, Ketchikan 7b) with a 159–240 day frost-free season — longer than much of the mountain West — yet cloudy, cool, extremely wet maritime summers on acidic, boggy Tongass soils mean heat-lovers like tomatoes and corn stall out while cool-season greens, brassicas, potatoes, rhubarb, and berries thrive. This is the mirror image of Alaska's cold-but-sunny Interior and cannot share a page with it. Well-matched crops include cabbage, potato, kale, and rhubarb, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
The Southeast Alaska / Inside Passage Panhandle spans Alaska.
Your yard isn't all of the Southeast Alaska / Inside Passage Panhandle.
The Southeast Alaska / Inside Passage Panhandle spans USDA zones 5a-8a, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Southeast Alaska / Inside Passage Panhandle — soil, climate, flood, and parcel records. How we handle your address.
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The Southeast Alaska / Inside Passage Panhandle — the short answer
The Southeast Alaska / Inside Passage Panhandle: USDA zones 5a-8a, 159–240 frost-free days depending where in it you stand, in Alaska.
- USDA zones
- 5a-8a
- USDA PHZM 2023, aggregated over the footprint
- Shortest season here
- 159 days
- NOAA Regional Climate Centers ACIS, 1991-2020 — Yakutat County
- Counties
- 10
- US Census TIGER/Line 2025
- Region type
- County cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. The season figure is this region's own record, measured across its 10 member counties, not a state or national average.
Hardiness Zone Range
The Southeast Alaska / Inside Passage Panhandle is not one growing season
One answer for the Southeast Alaska / Inside Passage Panhandle averages 10 counties whose growing seasons are 81 days apart — from 159 frost-free days in Yakutat County to 240 in Sitka County. That is the same region, measured the same way, in the same years. Which end of it your land sits nearer decides what finishes before the first hard freeze.
The middle half of 10 counties runs 195–220 days, with a median of 199 days — a 81-day span end to end.
Measured across 10 member counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020. A member with no own record is absent from the range rather than counted as zero — nothing here is interpolated to the region. Your own site sits somewhere inside this range; a parcel report resolves where.
Where the line runs inside the Southeast Alaska / Inside Passage Panhandle
The middle half of the Southeast Alaska / Inside Passage Panhandle runs 195–220 frost-free days, and 5 of its 10 counties sit outside that — 2 on the short side, 3 on the long. A regional planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 195 frost-free days
2 counties
- Yakutat County · 159 days
- Juneau County · 180 days
The end of the region that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
195–220 frost-free days
5 counties
0 of 5 shown
The middle half of the region, and the part a single regional season describes well.
Over 220 frost-free days
3 counties
- Sitka County · 240 days
- Hoonah-Angoon County · 237 days
- Ketchikan Gateway County · 223 days
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its OWN 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a site within its county as well — which is the part only your address resolves.
What Grows in the Southeast Alaska / Inside Passage Panhandle
All 1 of the plants below that publish a season requirement clear even Yakutat County’s 159 frost-free days — so on season alone, this grid works at both ends of the region. The 81-day spread still decides how far past this list you can push, and how early you can start.
Plants matched to the Southeast Alaska / Inside Passage Panhandle's USDA zones 5a-8a, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of the Southeast Alaska / Inside Passage Panhandle
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets the Southeast Alaska / Inside Passage Panhandle’s USDA zones 5a-8a — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
The ground across the Southeast Alaska / Inside Passage Panhandle
The USDA soil survey maps this ground county by county. These are those records weighted by land area across five member counties — this region’s own profile, not a state figure.
The ground is predominantly Entisols, at 39% of mapped acres, followed by Spodosols (27%), Histosols (20%) and Inceptisols (14%). Six soil orders appear somewhere inside the footprint, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Tolstoi, McGilvery, and Kina.
17% of those acres are well drained, and another 11% very poorly drained, 7% moderately well drained. Topsoil pH runs 4.0–6.2 between the lowest and the highest county on record.
Soil order
Entisols
Drainage
Well drained
Topsoil pH
4.0–6.2
Hydric soils
30%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Ketchikan Gateway County holds the most wetland ground here, at 51% — soil types explained.
USDA NRCS SSURGO via Soil Data Access · 5 of 10 footprint counties carry a summarizable record; the rest are absent from these figures rather than estimated.
What this means for growing in the Southeast Alaska / Inside Passage Panhandle
The soil survey reads this ground county by county, and the readings above are those records summed across the Southeast Alaska / Inside Passage Panhandle. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records17% of the mapped acres across the Southeast Alaska / Inside Passage Panhandle are well drained — ground that drains quickly. That is area-weighted across all five of its mapped counties.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
From county recordsTopsoil across the Southeast Alaska / Inside Passage Panhandle runs pH 4.0–6.2 — acidic in all five of them.
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
Wet ground
From county recordsAbout 30% of the ground across the Southeast Alaska / Inside Passage Panhandle is mapped as hydric — wetland — soil. Ketchikan Gateway County carries the most, at 51%.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Safe to Grow Here?
What the federal record shows across the Southeast Alaska / Inside Passage Panhandle — and how to grow with it.
Across the Southeast Alaska / Inside Passage Panhandle's 10 counties the federal record holds 2,124 documented sites, mostly Mining (1,435), Underground Storage Tanks (303) and Brownfields (198). The heaviest single county is Prince of Wales-Hyder County, with 564.
That is a regional count, not a reading of any one lot — proximity to a documented site is information, not a diagnosis. Open the map outlined to the Southeast Alaska / Inside Passage Panhandle to see which records sit where you actually grow.
Sources Checked
Summed across the 10 counties in the Southeast Alaska / Inside Passage Panhandle
A note from Gnorman
What an experienced grower watches for around here
In and around the Southeast Alaska / Inside Passage Panhandle, two things run higher than the national average across the 10 counties in the Southeast Alaska / Inside Passage Panhandle — Mining (1,435 sites) and Superfund (42 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the Southeast Alaska / Inside Passage Panhandle
Everything above resolves to the Southeast Alaska / Inside Passage Panhandle as a whole — a footprint whose own counties record seasons 81 days apart, and hardiness across zones 5a-8a. Your parcel sits at one point in that range, not in the middle of it. 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 region 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 regional average.
Your Lot vs the Southeast Alaska / Inside Passage Panhandle Average
Southeast Alaska / Inside Passage Panhandle Average
- ●USDA Zones 5a-8a, averaged across Southeast Alaska / Inside Passage Panhandle
- ●One soil character for all of Southeast Alaska / Inside Passage Panhandle
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Southeast Alaska / Inside Passage Panhandle's 5a-8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Southeast Alaska / Inside Passage Panhandle
Pull a site-specific report for your exact address in the Southeast Alaska / Inside Passage Panhandle — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Southeast Alaska / Inside Passage Panhandle averages can't show:
We read public map data around The Southeast Alaska / Inside Passage Panhandle — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Southeast Alaska / Inside Passage Panhandle average
How we know this about the Southeast Alaska / Inside Passage Panhandle
The boundary: a cluster of neighboring counties. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the counties inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about the Southeast Alaska / Inside Passage Panhandle
What hardiness zone is the Southeast Alaska / Inside Passage Panhandle?
The Southeast Alaska / Inside Passage Panhandle spans USDA hardiness zones 5a-8a, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's counties. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the Southeast Alaska / Inside Passage Panhandle?
Measured between 28°F hard freezes, the Southeast Alaska / Inside Passage Panhandle's counties mostly run 195 to 220 frost-free days, median 199 (NOAA Regional Climate Centers ACIS, 1991–2020, over 10 member counties). That 25-day spread is the honest read — no single season describes 10 counties, and each county guide below carries its own.
When does frost risk end in the Southeast Alaska / Inside Passage Panhandle?
Across the Southeast Alaska / Inside Passage Panhandle, the middle half of member counties see their last 28°F hard freeze between Apr 3 and Apr 16 (median Apr 14), and their first fall freeze between Oct 27 and Nov 10. Those are hard freezes, not the last light frost: tender transplants wait for about May 5, and elevation decides which end of a 13-day spread you garden in.
What grows well in the Southeast Alaska / Inside Passage Panhandle?
The Southeast Alaska / Inside Passage Panhandle's conditions suit plants such as Cabbage, Potato, Kale, Rhubarb, Sitka Spruce. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is the Southeast Alaska / Inside Passage Panhandle defined?
The Southeast Alaska / Inside Passage Panhandle is defined here as a curated cluster of 10 neighboring counties that share a growing character. Growing regions have no official boundary, so this footprint is our published one — every county in it is named on this page.
Which states does the Southeast Alaska / Inside Passage Panhandle cover?
The Southeast Alaska / Inside Passage Panhandle spans Alaska. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Interior Alaska / Tanana Valley (Fairbanks), Kenai Peninsula Coast, and Matanuska–Susitna Valley (Mat-Su) share at least one state with the Southeast Alaska / Inside Passage Panhandle. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at the Southeast Alaska / Inside Passage Panhandle’s own scale
6 of the readings below were taken at the Southeast Alaska / Inside Passage Panhandle's own scale — the zone 5a-8a band across its footprint, a median 199-day season across its 10 counties and 2,124 documented federal contamination records across its 10 counties, 564 of them in Prince of Wales-Hyder County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 5a-8a aggregated across all 10 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 10 counties this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The 28°F season across the footprint — the middle half of its 10 counties run 195 to 220 frost-free days, median 199NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 2,124 documented federal contamination records across its 10 counties, 564 of them in Prince of Wales-Hyder County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 39% Entisols, topsoil pH 4.0–6.2, area-weighted across its 5 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 5a-8afrom Alaska
What this page can’t tell you
- Which end of the 25-day range your ground sits at — 195 days at one extreme, 220 at the other, decided mostly by elevationfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore the Southeast Alaska / Inside Passage Panhandle
State growing guides
Counties in this region
Other growing regions across Alaska
Interior Alaska grows on a knife-edge no other American garden shares: a continental cold pocket where winters bottom out near -40F and the region spans zone 1b-4a, its inhabited Tanana floor running roughly 1b-2b — among the coldest settled hardiness zones in the country — yet Fairbanks summers deliver up to ~21 hours of daylight. That midnight sun is the trade: cold-hardy, quick-maturing varieties sprint through an ~85-118 day frost-free window (as short as 85 days out toward Delta Junction and Tok). Success here is a distinct discipline built on high tunnels, short-season cultivars, and exploiting long light — nothing about it resembles the maritime panhandle or the milder Mat-Su, and the coarse state page (a flat 3a-4b) cannot express a 1b-4a region whose settled floor sits at the cold end of that band on a ~90-day season.
Cook Inlet's maritime edge — from Homer's 6b banana-belt bluffs to Seward's 7a harbor, ocean-moderated pockets that garden far milder than the peninsula's interior river flats, on committed place records spanning 4b-7a.
Alaska's farm heartland — the Mat-Su's long June days grow the state fair's giant cabbages on a 4a-5b valley floor whose committed band runs two zones warmer than the borough's glacier-to-Denali average.