Dukes County, in Massachusetts, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Expect cabbage, hazelnut, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
You’re in Cape Cod & the Islands
A sandy, sea-wrapped peninsula and islands with the state's warmest, longest season — and its most maritime one. Acidic soils long worked for cranberries and beach plums; wind and salt are the constant neighbors of every garden.
Dukes County holds more than one microclimate.
Soils and elevations shift across Dukes 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 Dukes County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Dukes County — the short answer
Dukes County, Massachusetts: USDA zone 7a, about 211 days between hard freezes, across 66K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 14
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 11
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~211
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 66K 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 Dukes County's average, not your lot's — a low corner or a tree line moves it. Against Dukes County's 211-day season, see what your own ground reads.
Heat in Dukes County
Across a year, Dukes County accumulates about 2,559 growing degree days above 50°F, about 33 more than the middle Massachusetts county — ahead of 8 of Massachusetts’s 14 counties. 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 Dukes County
Across Dukes County, the ground is predominantly Entisols, where Carver, Eastchop, and Riverhead are the most extensive named soil series. The soil is generally excessively drained with a loamy coarse sand surface. Topsoil pH runs about 4.0–4.8, extremely acidic. Rainfall drains through hydrologic group A soils.
Soil order
Entisols
Drainage
Excessively drained
Prime farmland
16%
Hydric soils
9%
Soil still varies lot by lot — soil types explained.
How the ground varies across Dukes County
The USDA soil survey maps 52% of Dukes County as excessively drained — but another 31% drains differently: 21% well drained, 5% very poorly drained.
Carver is the most extensive named soil at 34% of mapped acres, then Eastchop (19%) and Riverhead (11%).
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 Dukes County
Each reading below is measured for Dukes 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 Dukes County are excessively drained, in hydrologic group A — 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 Dukes County runs about pH 4.0–4.8, 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
Season length
MeasuredDukes County runs about 211 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
Winter hardiness
MeasuredDukes County sits in USDA hardiness zone 7a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Dukes County is in
Dukes County sits in the Atlantic Coastal Pine Barrens — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Dukes County
We scored all 1,086 plants against Dukes County's own USDA zone 7a and its own 211-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 Massachusetts profile.
Is it too late to plant in Dukes County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 11 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Dukes County
Spotted lanternfly documented 2 miles from Dukes County, first recorded 2020. What to watch for.
- Japanese beetle8 documented records
- monarch butterfly97 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Dukes County
USGS estimates 114 lb of Glyphosate on Dukes County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (106 lb) and Atrazine (72 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 Dukes County — and how to grow with it.
We checked the federal record across Dukes County — 140 documented sites across 6 of the 9 source types we track.
The most significant on record: 1 Superfund site (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 Dukes 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 Dukes County
Closest first, across Dukes County. Listing isn't leaking, and distance isn't exposure.
- MERMAID FARMBrownfields · 2400 ft
- NRG CANAL LLC - WEST TISBURYBrownfields · 1.1 mi
- MID ISLAND REPAIR INCBrownfields · 1.4 mi
- UP-ISLAND AUTOMOTIVE INCUnderground Storage Tanks · 1.4 mi
- WALTER JENKINSON IIIUnderground Storage Tanks · 1.7 mi
- SEVEN GATES FARM CORPUnderground Storage Tanks · 2.1 mi
- KELLMAN RESIDENCEBrownfields · 2.5 mi
- OLSEN BROTHERS CO INCUnderground Storage Tanks · 2.5 mi
- JOHN KEENE EXCAVATION INCBrownfields · 2.5 mi
- MARTHA'S VINEYARD AIRPORTUnderground Storage Tanks · 2.6 mi
- WEST TISBURY GENERATING STATIONUnderground Storage Tanks · 2.6 mi
- FINE FETTLE ENTERPRISES MABrownfields · 2.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Dukes 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 Dukes County.
Total Sites
140
across Dukes County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Dukes County
Severity Distribution
across Dukes County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dukes County, two things run higher than the national average across Dukes County — PFAS (3 sites) and Brownfields (77 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Dukes 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 Dukes County average
Your land is one point inside Dukes County
Everything above resolves to Dukes County as a whole — one PHZM band and one county frost record, read across 66K 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 Dukes County Average
Dukes County Average
- ●USDA Zones 7a, averaged across Dukes County
- ●One soil character for all of Dukes County
- ●Frost dates read at Dukes County's scale: Apr 14 to Nov 11
YOUR Parcel
- ✓Your exact zone, not Dukes County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Dukes County
Pull a site-specific report for your exact address in Dukes County, Massachusetts — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dukes County averages can't show:
We read public map data around Dukes County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dukes County average
How we know this about Dukes 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 Dukes County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Dukes County
When does frost risk typically end in Dukes County?
The last hard freeze (28°F) in Dukes County typically lands around Apr 14, 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 May 5.
How long is the growing season in Dukes County?
Measured between 28°F hard freezes, Dukes County sees about 211 frost-free days — roughly Apr 14 through Nov 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 5 to Oct 28, about 176 days.
Is the soil safe to grow vegetables in Dukes County?
The federal record around Dukes County is a meaningful one — 140 documented sites, mostly Brownfields entries (77), the nearest Brownfields record about 0.5 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 Dukes County's scale — its 7a band and its 211-day season. Your yard writes its own version of Dukes 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 Massachusetts's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Dukes County’s own scale
9 of the readings below were taken at Dukes County's own scale — its own ~211-day span between 28°F freezes, the 3 most extensive soil series mapped here and 140 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Dukes County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Dukes County's own 28°F hard-freeze dates and its ~211-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Dukes CountyUSDA NRCS SSURGO
- 140 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.5 miles outFederal environmental registers
- Dukes County's boundary and the 66,050 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~211-day seasonGrowable Ground crop-matching engine
- Dukes County sitting wholly inside the Atlantic Coastal Pine BarrensUS EPA Level III Ecoregions
- Open occurrence records documented in Dukes County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Dukes County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Massachusetts grower plans around — written at state scale, so they stay on the state guidefrom Massachusetts
What this page can’t tell you
- How the season shifts across Dukes County — the ~211 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 Dukes County's 66,050 acreswhy one lot differs from the next →
- Which of those 140 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 Dukes Countyread your own land →