Conditional — Some Areas
marionberry (zones 6-9) reaches only part of Vermont (4a-6a): zone 6 are in range, so where you are in the state decides it.
One zone short — what would close it
Marionberry is hardy to zone 6, and the warmest ground in Vermont is zone 5 — 1 zone short. Planted in open ground it will not survive a Vermont winter. To grow it here, grow marionberry in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 6-9 (plant) against 3-5 (Vermont). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Marionberry in Vermont — the short answer
Marionberry in Vermont: hardy in zones 6–9, full sun, against a state median of ~163 frost-free days.
- Plant zones
- 6-9
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Vermont zones
- 4a-6a
- USDA PHZM 2023
- Frost window
- Apr 27 - May 5 – Oct 10 - Oct 17
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 146 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Vermont spans zones 4a-6a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score marionberry against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Vermont is not one climate
Vermont’s winter-low ladder runs across 14 counties, from zone 4.5 in Caledonia County to zone 5.5 in Windsor County. That is 10°F between the two counties’ average coldest night — the difference between marionberry overwintering in the ground and coming under cover.
The middle half of 14 counties runs 4.5–5 zones, with a median of 5 zones — a 1-zone span end to end.
Measured across 14 Vermont counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where Marionberry Stands in Vermont
Marionberry is rated for zones 6–9 — a cold floor USDA puts at -10 to 0°F. No Vermont county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Vermont winters, not about marionberry.
Below the zone 6 floor
14 counties
- Caledonia County · zone 4b
- Essex County · zone 4b
- Franklin County · zone 4b
3 of 14 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Zone Comparison
Marionberry Needs
- USDA Zones: 6-9
- Frost-Free Days: 120+
- Sun: Full Sun
- Mature size: 5 ft tall
- Picking window: ~28 days of harvest
- Drought tolerance: Medium
Vermont Has
- USDA Zones: 4a-6a
- Last Hard Freeze (28°F): Apr 27 - May 5
- First Hard Freeze (28°F): Oct 10 - Oct 17
- Annual Rainfall: 34-44 inches
- Common Soils: Glacial till, Clay, Silt loam
Plant Zone Range (zones 6-9)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Marionberry in Vermont
The frost window
Across Vermont, the last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 158-day window you can count on — up to 173 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Winter standing
Vermont runs as cold as USDA zone 4, and no sourced winter-hardiness floor is on record for marionberry, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether marionberry is a permanent planting or a replant-every-spring crop for you turns on your own zone within Vermont; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Essex County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says marionberry survives winter in part of Vermont, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Marionberry wants 120+ frost-free days; a typical Vermont site sees ~163 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a workable window — start indoors to bank time.
Growing degree days
Marionberry needs ~1800 GDD (base 50°F) to ripen. The state median runs ~1746 GDD (from PRISM 1991-2020 climate normals), so Vermont's typical season runs short on heat — pick a south-facing site and consider season extension.
Chill hours
Marionberry requires ~300 chill hours (32-45°F dormancy window). Vermont typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Marionberry tolerates a wide pH range (pH 4.5-7.8) — 3.3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Vermont. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 6.5 — worth knowing before you decide whether a Vermont soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Vermont site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
SSURGO maps about 18.5% of Vermont as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Marionberry sits mid-range for drought tolerance, so either extreme can cost you — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Vermont soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant marionberry for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before marionberry goes in. What follows is Vermont’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
Safe to Grow Here?
What the federal record shows across Vermont — and how to grow with it.
We checked the federal record across Vermont — 6,987 documented sites across 8 of the 9 source types we track.
The most significant on record: 41 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Vermont 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 Checked
across Vermont
Severity Distribution
across Vermont
Highest-Severity Sites
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.
What Else to Consider for Marionberry in Vermont
Zone compatibility tells you about winter cold survival — but Vermont growers also need to think about:
Short growing season (100-130 frost-free days)
Rocky soils throughout the Green Mountains
Heavy clay in the Champlain Valley
Growing marionberry here specifically
Marionberry roots run deep and prefer pH 4.5–7.8, but drainage comes first here: SSURGO maps about 18.5% of Vermont as poorly or somewhat-poorly drained, and wet ground rots its crown before pH ever matters.
Plant marionberry on a raised, gravel-amended berm so water drains fast and the crown stays dry. How to handle it →
What to actually do about these — and the constraints that apply to every Vermont grower, not just marionberry — is covered on the Vermont growing guide.
Timing shifts within Vermont
Vermont isn't one climate. In Essex County, the last hard freeze (28°F) holds until about May 13 — roughly 11 days later than the recorded state median — so plant marionberry to your county's window, not the statewide date.
Marionberry needs about 120 days of frost-free season to complete its cycle. Even Essex County — Vermont’s shortest season at 146 frost-free days — clears that by 26 days, so season length isn’t the constraint anywhere in Vermont. What varies is your own parcel.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Marionberry's 120-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Marionberry draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, marionberry can only work that bloom inside Vermont's frost window — roughly 163 days, opening after the last 28°F freeze (Apr 27 - May 5) and closing at the first (Oct 10 - Oct 17), per NOAA Regional Climate Centers ACIS, 1991-2020.
Vermont Cooperative Extension
For Vermont-specific cultivar recommendations, planting calendars, and pest pressure for marionberry, the canonical source is UVM Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Marionberry in Vermont
When can I plant Marionberry in Vermont?
Vermont's last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Marionberry, so this page does not state whether it overwinters in Vermont and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Marionberry grown in across Vermont?
Vermont spans USDA hardiness zones 4a-6a (USDA ARS PHZM 2023). Marionberry carries a range of zones 6-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Vermont site have?
A typical Vermont site sees ~163 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Marionberry needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Essex, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Marionberry in Vermont?
Marionberry tolerates pH 4.5-7.8 and well (dry spells) drainage (FAO ECOCROP). That is a 3.3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Vermont site — amend for drainage and organic matter first.
Will Marionberry actually grow on my specific land in Vermont?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores marionberry against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Vermont
State-level data is a sketch. Your Growable Ground report scores marionberry against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Vermont marionberry averages can't show:
We read public map data around Vermont — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Vermont marionberry average
Explore More
Growing guides for marionberry
Explore Vermont county by county
Vermont carries 14 counties with their own USDA zone — a sample of the growing pages for marionberry there:
Where else marionberry grows
Marionberry's zone band crosses state lines — these are the states closest to Vermont in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Vermont
Vermont has a growing page for 747 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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