Unlikely — Zone Mismatch
American joint vetch (zones 8-11) does not overlap with Rhode Island's zone range (6b-7b). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
American Joint Vetch is hardy to zone 8, and the warmest ground in Rhode Island is zone 7 — 1 zone short. Planted in open ground it will not survive a Rhode Island winter. To grow it here, grow american joint vetch 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 8-11 (plant) against 6-7 (Rhode Island). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
American Joint Vetch in Rhode Island — the short answer
American Joint Vetch in Rhode Island: hardy in zones 8–11, full sun.
- Plant zones
- 8-11
- Not verified
- Rhode Island zones
- 6b-7b
- USDA PHZM 2023
- Frost window
- Mar 27 - Apr 3 – Nov 7 - Nov 21
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 210 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.
Rhode Island spans zones 6b-7b, 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 american joint vetch 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 parcel report in seconds — read in full free for your first 14 days
Where American Joint Vetch Stands in Rhode Island
American Joint Vetch is rated for zones 8–11 — a cold floor USDA puts at 10 to 20°F. No Rhode Island 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 Rhode Island winters, not about american joint vetch.
Below the zone 8 floor
5 counties
- Kent County · zone 6b
- Providence County · zone 6b
- Bristol County · zone 7a
3 of 5 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
American Joint Vetch Needs
- USDA Zones: 8-11
- Sun: Full Sun
- Mature size: 3 ft tallWe haven't confirmed this against a published source yet.
Rhode Island Has
- USDA Zones: 6b-7b
- Last Hard Freeze (28°F): Mar 27 - Apr 3
- First Hard Freeze (28°F): Nov 7 - Nov 21
- Annual Rainfall: 44-52 inches
- Common Soils: Glacial till, Sandy loam, Coastal sand
Plant Zone Range (zones 8-11)
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 American Joint Vetch in Rhode Island
The frost window
Across Rhode Island, the last spring hard freeze (28°F) clears between Mar 27 and Apr 3, and the first fall hard freeze lands between Nov 7 and Nov 21 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 218-day window you can count on — up to 239 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
Rhode Island runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for american joint vetch, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether american joint vetch is a permanent planting or a replant-every-spring crop for you turns on your own zone within Rhode Island; check its hardiness range against that before treating it as long-lived ground.
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.
Soil + Drainage Fit
American Joint Vetch tolerates a wide pH range (pH 4-8) — 4 units, acid ground through alkaline — so soil acidity is rarely what limits it in Rhode Island. 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 7 — worth knowing before you decide whether a Rhode Island soil test result is a problem or just a number. Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.
Your land, not the state average
Rhode Island's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. American Joint Vetch needs about 7 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how american joint vetch 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. Rhode Island soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for American Joint Vetch in Rhode Island
Zone compatibility tells you about winter cold survival — but Rhode Island growers also need to think about:
Small lot sizes limit garden space in much of the state
Salt spray affects coastal plantings
Rocky glacial soils need clearing
Growing american joint vetch here specifically
American Joint Vetch wants pH 4.0–8.0 and rates to USDA zones 8–11, but Rhode Island's soils are dominantly fine sandy loam — the fit is decided by your parcel's own map unit, not the state average.
Match american joint vetch to your parcel's SSURGO map unit — test pH and texture, and amend toward its 4.0–8.0 range. How to handle it →
What to actually do about these — and the constraints that apply to every Rhode Island grower, not just american joint vetch — is covered on the Rhode Island growing guide.
Where in Rhode Island American Joint Vetch Is Zone-Hardy
American Joint Vetch is rated for USDA zones 8–11. No Rhode Island county reaches it. Even Washington County, the state’s mildest winter at zone 7a, sits below the plant’s zone 8 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. American Joint Vetch’s zone 8–11 band: Not verified. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
American Joint Vetch draws honeybees and native bees (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, american joint vetch can only work that bloom inside Rhode Island's frost window — roughly 225 days, opening after the last 28°F freeze (Mar 27 - Apr 3) and closing at the first (Nov 7 - Nov 21), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.
Rhode Island Cooperative Extension
For Rhode Island-specific cultivar recommendations, planting calendars, and pest pressure for american joint vetch, the canonical source is URI Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is American Joint Vetch native to Rhode Island?
American Joint Vetch is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-10-19) does not record it growing in Rhode Island. It can still earn a place in a Rhode Island garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Rhode Island growing guide lists plants that USDA PLANTS records growing in Rhode Island and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.
State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.
Common Questions About Growing American Joint Vetch in Rhode Island
When can I plant American Joint Vetch in Rhode Island?
Rhode Island's last spring hard freeze (28°F) clears between Mar 27 and Apr 3, and the first fall hard freeze lands between Nov 7 and Nov 21 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for American Joint Vetch, so this page does not state whether it overwinters in Rhode Island 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 American Joint Vetch grown in across Rhode Island?
Rhode Island spans USDA hardiness zones 6b-7b (USDA ARS PHZM 2023). American Joint Vetch is listed for zones 8-11, which do not overlap them, so there is no zone in Rhode Island where this page can call outdoor growing reliable. A parcel report resolves your own address's zone.
How many frost-free days does a typical Rhode Island site have?
A typical Rhode Island site sees ~225 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). American Joint Vetch needs 60+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is American Joint Vetch native to Rhode Island?
American Joint Vetch is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-10-19) does not record it growing in Rhode Island. It can still earn a place in a Rhode Island garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for American Joint Vetch in Rhode Island?
American Joint Vetch tolerates pH 4-8 and poorly (saturated >50% of year) drainage (FAO ECOCROP). That is a 4-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Rhode Island site — amend for drainage and organic matter first.
Will American Joint Vetch actually grow on my specific land in Rhode Island?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores american joint vetch against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Rhode Island
State-level data is a sketch. Your Growable Ground report scores american joint vetch against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Rhode Island american joint vetch averages can't show:
We read public map data around Rhode Island — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rhode Island american joint vetch average
Explore More
Growing guides for american joint vetch
Explore Rhode Island county by county
Rhode Island carries 5 counties with their own USDA zone — a sample of the growing pages for american joint vetch there:
Where else american joint vetch grows
American Joint Vetch's zone band crosses state lines — these are the states closest to Rhode Island 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 Rhode Island
Rhode Island has a growing page for 882 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: