Bristol County, in Rhode Island, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
On paper, cabbage, hazelnut, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Bristol County holds more than one microclimate.
Soils and elevations shift across Bristol County, so your frost dates and drainage aren't the county average. 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 Bristol County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Bristol County — the short answer
Bristol County, Rhode Island: USDA zone 7a, about 239 days between hard freezes, across 15K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 27
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~239
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 15K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7a is Bristol County's average, not your lot's — a low corner or a tree line moves it. Against Bristol County's 239-day season, see what your own ground reads.
Heat in Bristol County
Across a year, Bristol County accumulates about 2,888 growing degree days above 50°F, about 253 more than the middle Rhode Island county — ahead of every other Rhode Island county. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Bristol County
Across Bristol County, the ground is predominantly Inceptisols, where Merrimac, Newport, and Pittstown are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 5.1–5.3, strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Inceptisols
Drainage
Well drained
Prime farmland
21%
Hydric soils
23%
Soil still varies lot by lot — soil types explained.
How the ground varies across Bristol County
The USDA soil survey maps 16% of Bristol County as well drained — but another 38% drains differently: 13% moderately well drained, 12% somewhat excessively drained.
Merrimac is the most extensive named soil at 16% of mapped acres, then Newport (14%) and Pittstown (14%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Bristol County
Each reading below is measured for Bristol County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Bristol County are well drained, in hydrologic group C — ground that drains quickly.
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
MeasuredTopsoil across Bristol County runs about pH 5.1–5.3, on the acidic side.
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
MeasuredAbout 23% of Bristol County is mapped as hydric — wetland — soil.
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
Season length
MeasuredBristol County runs about 239 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
The kind of country Bristol County is in
Bristol County sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Bristol County
We scored all 1,086 plants against Bristol County's own USDA zone 7a and its own 239-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Rhode Island profile.
Is it too late to plant in Bristol County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Bristol County
Spotted lanternfly documented 6 miles from Bristol County, first recorded 2021. What to watch for.
- Japanese beetle3 documented records
- monarch butterfly6 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Bristol County
USGS estimates 53 lb of Glyphosate on Bristol County farmland in 2019, its largest by weight, ahead of Atrazine (43 lb) and Metolachlor & Metolachlor-s (35 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Bristol County — and how to grow with it.
We checked the federal record across Bristol County — 264 documented sites across 5 of the 9 source types we track.
The most significant on record: 4 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Bristol County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Bristol County
Closest first, across Bristol County. Listing isn't leaking, and distance isn't exposure.
- NORTH FARMUnderground Storage Tanks · 1800 ft
- SERPA'S INCUnderground Storage Tanks · 2400 ft
- TRI-MACK PLASTIC MFG. CORPBrownfields · 0.6 mi
- CARBON OCEAN YACHTSBrownfields · 0.6 mi
- LOCOUST ST. PUMP STATIONUnderground Storage Tanks · 0.7 mi
- MHRH CORPORATIONUnderground Storage Tanks · 0.7 mi
- PITSTOP CONVENIENCE AND FUEL, INC.Underground Storage Tanks · 0.7 mi
- RI D O T MAINTENANCE DIVBrownfields · 0.9 mi
- VIVE COLLISION D/B/A CROWN COLLISION CENTERS - BRISTOLBrownfields · 0.9 mi
- CARROLL MARINE LTDBrownfields · 0.9 mi
- CARROLL MARINE LTDToxics Release Inventory · 0.9 mi
- WARREN GARAGE (D.O.T.)Underground Storage Tanks · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Bristol County's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Bristol County.
Total Sites
264
across Bristol County
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
across Bristol County
Severity Distribution
across Bristol County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bristol County, two things run higher than the national average across Bristol County — Superfund (4 sites) and Toxics Release Inventory (19 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Bristol County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Bristol County average
Your land is one point inside Bristol County
Everything above resolves to Bristol County as a whole — one PHZM band and one county frost record, read across 15K acres. Your parcel is one point inside that footprint. 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 county 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 county average.
Your Lot vs the Bristol County Average
Bristol County Average
- ●USDA Zones 7a, averaged across Bristol County
- ●One soil character for all of Bristol County
- ●Frost dates read at Bristol County's scale: Mar 27 to Nov 21
YOUR Parcel
- ✓Your exact zone, not Bristol County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Bristol County
Pull a site-specific report for your exact address in Bristol County, Rhode Island — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bristol County averages can't show:
We read public map data around Bristol County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bristol County average
How we know this about Bristol County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Bristol County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Bristol County
When does frost risk typically end in Bristol County?
The last hard freeze (28°F) in Bristol County typically lands around Mar 27, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 17.
How long is the growing season in Bristol County?
Measured between 28°F hard freezes, Bristol County sees about 239 frost-free days — roughly Mar 27 through Nov 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 17 to Nov 7, about 204 days.
Is the soil safe to grow vegetables in Bristol County?
The federal record around Bristol County is a meaningful one — 264 documented sites, mostly Underground Storage Tanks entries (147), the nearest Underground Storage Tanks record about 0.3 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
Everything above is measured at Bristol County's scale — its 7a band and its 239-day season. Your yard writes its own version of Bristol County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Rhode Island's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Bristol County’s own scale
9 of the readings below were taken at Bristol County's own scale — its own ~239-day span between 28°F freezes, the 3 most extensive soil series mapped here and 264 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Bristol County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Bristol County's own 28°F hard-freeze dates and its ~239-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Bristol CountyUSDA NRCS SSURGO
- 264 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Bristol County's boundary and the 15,444 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~239-day seasonGrowable Ground crop-matching engine
- Bristol County sitting wholly inside the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- Open occurrence records documented in Bristol County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Bristol County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Rhode Island grower plans around — written at state scale, so they stay on the state guidefrom Rhode Island
What this page can’t tell you
- How the season shifts across Bristol County — the ~239 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bristol County's 15,444 acreswhy one lot differs from the next →
- Which of those 264 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Bristol Countyread your own land →