Conditional — Some Areas
inkberry (zones 6-12) 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
Inkberry 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 inkberry 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 6-12 (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.
Inkberry in Vermont — the short answer
Inkberry in Vermont: hardy in zones 6–12, full sun, against a state median of ~163 frost-free days.
- Plant zones
- 6-12
- 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 inkberry 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.
No card required · your full report in seconds
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 inkberry 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 Inkberry Stands in Vermont
Inkberry is rated for zones 6–12 — 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 inkberry.
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
Inkberry Needs
- USDA Zones: 6-12
- Sun: Full Sun
- Mature size: 8 ft tall
- Picking window: ~28 days of harvest
- Drought tolerance: Low
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 6-12)
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 Inkberry 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 inkberry, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether inkberry 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 inkberry survives winter in part of Vermont, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Chill hours
Inkberry requires ~400 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
Inkberry likes near-neutral soil (pH 4.5-7). That's the common-ground band across Vermont's glacial till and clay — a soil test confirms it for your site. 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
Vermont's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for inkberry is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how inkberry performs.
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.
What Else to Consider for Inkberry 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 inkberry here specifically
Inkberry wants pH 4.5–7.0 and rates to USDA zones 6–12, but Vermont's soils are dominantly fine sandy loam — the fit is decided by your parcel's own map unit, not the state average.
Match inkberry to your parcel's SSURGO map unit — test pH and texture, and amend toward its 4.5–7.0 range. How to handle it →
What to actually do about these — and the constraints that apply to every Vermont grower, not just inkberry — 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 inkberry to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Vermont Inkberry Is Zone-Hardy
Inkberry is rated for USDA zones 6–12. No Vermont county reaches it. Even Windsor County, the state’s mildest winter at zone 5b, sits below the plant’s zone 6 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
Across those 14 counties Vermont’s winter-low ladder runs from zone 4b in Caledonia County to zone 5b in Windsor County — 1 USDA zone of spread, which is 10°F between the two counties’ average coldest night of the year. None of that range reaches the band inkberry needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Inkberry’s zone 6–12 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Inkberry draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, inkberry 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.
Good to Know Before You Plant Inkberry
Inkberry is listed as toxic to dogs, cats (berries) at a mild level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Vermont Cooperative Extension
For Vermont-specific cultivar recommendations, planting calendars, and pest pressure for inkberry, the canonical source is UVM Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Inkberry native to Vermont?
Inkberry is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Vermont. It can still earn a place in a Vermont garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Vermont growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Inkberry in Vermont
When can I plant Inkberry 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 Inkberry, 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 Inkberry grown in across Vermont?
Vermont spans USDA hardiness zones 4a-6a (USDA ARS PHZM 2023). Inkberry carries a range of zones 6-12, 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). Inkberry should be matched against that window, 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.
Is Inkberry native to Vermont?
Inkberry is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Vermont. It can still earn a place in a Vermont garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for Inkberry in Vermont?
Inkberry prefers pH 4.5-7 and well (dry spells) drainage (USDA PLANTS). That sits in the common-ground band across Vermont soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Inkberry actually grow on my specific land in Vermont?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores inkberry 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 inkberry against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Vermont inkberry 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 inkberry average
Explore More
Growing guides for inkberry
Explore Vermont county by county
Vermont carries 14 counties with their own USDA zone — a sample of the growing pages for inkberry there:
Where else inkberry grows
Inkberry'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
Last updated: