The Southern Vermont spans USDA hardiness zone 5b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
The warmest ground in Vermont: Windham and Windsor are the state's only USDA zone 5b counties, running roughly two weeks longer at the shoulders (~159 frost-free days) than the 4b Northeast Kingdom behind them. The lower Connecticut and West River valleys around Brattleboro make this southern-Vermont market-garden and hillside-orchard country — the warm counterpoint the statewide 4b-5b Vermont page can't foreground. Crops well matched to these conditions include garlic, kale, sugar maple, and apple — though what thrives on any one site still turns on its specific soil, sun, and drainage.
The Southern Vermont spans Vermont.
Your yard isn't all of the Southern Vermont.
The Southern Vermont spans USDA zones 5b, 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 Southern Vermont — soil, climate, flood, and parcel records. How we handle your address.
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The Southern Vermont — the short answer
The Southern Vermont: USDA zones 5b, 158–161 frost-free days, in Vermont.
- USDA zones
- 5b
- USDA PHZM 2023, aggregated over the footprint
- Frost-free season
- 158–161 days
- NOAA Regional Climate Centers ACIS, 1991-2020
- Counties
- 2
- 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. Where a region publishes no measured season, no season figure is shown.
Hardiness Zone Range
What Grows in the Southern Vermont
Plants matched to the Southern Vermont's USDA zones 5b, 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 Southern Vermont
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets the Southern Vermont’s USDA zones 5b — 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 Southern Vermont
The USDA soil survey maps this ground county by county. These are those records weighted by land area across two member counties — this region’s own profile, not a state figure.
The ground is predominantly Spodosols, at 64% of mapped acres, followed by Inceptisols (31%), Entisols (4%) and Histosols (1%). The most extensive named soils are Tunbridge, Vershire, and Houghtonville.
59% of those acres are well drained, and another 15% moderately well drained, 11% somewhat excessively drained. Topsoil pH runs 4.6–5.5 between the lowest and the highest county on record. 3% of the footprint is classed prime farmland.
Soil order
Spodosols
Drainage
Well drained
Topsoil pH
4.6–5.5
Hydric soils
4%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Windham County holds the most wetland ground here, at 4% — soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the Southern Vermont
The soil survey reads this ground county by county, and the readings above are those records summed across the Southern Vermont. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records59% of the mapped acres across the Southern Vermont are well drained — ground that drains quickly. That is area-weighted across all two 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 Southern Vermont runs pH 4.6–5.5 — acidic in all two 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
Safe to Grow Here?
What the federal record shows across the Southern Vermont — and how to grow with it.
Across the Southern Vermont's 2 counties the federal record holds 1,311 documented sites, mostly Underground Storage Tanks (732), Brownfields (466) and Nitrate (42). The heaviest single county is Windsor County, with 728.
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 Southern Vermont to see which records sit where you actually grow.
Sources Checked
Summed across the 2 counties in the Southern Vermont
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the Southern Vermont
Everything above resolves to the Southern Vermont as a whole — a footprint spanning USDA zones 5b. Your parcel sits in exactly one of them. 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 Southern Vermont Average
Southern Vermont Average
- ●USDA Zones 5b, averaged across Southern Vermont
- ●One soil character for all of Southern Vermont
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Southern Vermont's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Southern Vermont
Pull a site-specific report for your exact address in the Southern Vermont — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Southern Vermont averages can't show:
We read public map data around The Southern Vermont — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Southern Vermont average
How we know this about the Southern Vermont
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 Southern Vermont
What hardiness zone is the Southern Vermont?
The Southern Vermont spans USDA hardiness zones 5b, 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 Southern Vermont?
Measured between 28°F hard freezes, the Southern Vermont's counties mostly run 159 to 160 frost-free days, median 160 (NOAA Regional Climate Centers ACIS, 1991–2020, over 2 member counties). That 1-day spread is the honest read — no single season describes 2 counties, and each county guide below carries its own.
When does frost risk end in the Southern Vermont?
Across the Southern Vermont, the middle half of member counties see their last 28°F hard freeze between May 4 and May 5 (median May 5), and their first fall freeze between Oct 11 and Oct 12. Those are hard freezes, not the last light frost: tender transplants wait for about May 26, and elevation decides which end of a 1-day spread you garden in.
What grows well in the Southern Vermont?
The Southern Vermont's conditions suit plants such as Garlic, Kale, Sugar Maple, Apple, Blueberry. 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 Southern Vermont defined?
The Southern Vermont is defined here as a curated cluster of 2 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 Southern Vermont cover?
The Southern Vermont spans Vermont. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Champlain Valley, The Green Mountains, The Northeast Kingdom, The Upper Valley, and Mad River Valley share at least one state with the Southern Vermont. 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 Southern Vermont’s own scale
6 of the readings below were taken at the Southern Vermont's own scale — the zone 5b band across its footprint, a median 160-day season across its 2 counties and 1,311 documented federal contamination records across its 2 counties, 728 of them in Windsor County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 5b aggregated across all 2 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 2 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 2 counties run 159 to 160 frost-free days, median 160NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 1,311 documented federal contamination records across its 2 counties, 728 of them in Windsor County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 64% Spodosols, topsoil pH 4.6–5.5, area-weighted across its 2 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 5bfrom Vermont
What this page can’t tell you
- Which end of the 1-day range your ground sits at — 159 days at one extreme, 160 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 Southern Vermont
State growing guides
Counties in this region
Other growing regions across Vermont
The lake-tempered lowland on both shores of Lake Champlain — clay and silt plains that make the warmest, driest, and most productive farm ground in Vermont, with apple and cold-climate wine country on the New York shore.
Vermont's forested spine of cold uplands and sheltered valleys — maple, apples, and cold-hardy market gardens on acidic mountain loams under a short northern season.
Vermont's Northeast Kingdom — Caledonia, Essex, and Orleans counties — sits entirely in USDA hardiness zone 4b, giving its three counties a short, uniformly cold frost-free season of roughly 146 to 156 days.
The Connecticut River's bi-state trench from Windsor to Hanover — 5a-5b valley-floor ground on both banks, warmer than the hills that rise from it, and a single growing community that has always ignored the state line.
A high Vermont valley cradled between the Green Mountain spine and the Northfield range — cold-air-pooling farm floors growing hay, brassicas, and hardy orchards under a short mountain season.