What Grows in Watch Hill, Rhode Island

USDA Zones 7a · 513 acres

Watch Hill, Rhode Island, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.

Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.

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Even in Watch Hill, no two yards are alike.

A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Watch Hill lot. 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 Watch Hill — soil, climate, flood, and parcel records. How we handle your address.

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Watch Hill — the short answer

Watch Hill, Rhode Island: USDA zone 7a, about 229 days between hard freezes, across 513 acres of town.

USDA zone
7a
USDA PHZM 2023
Last hard freeze (28°F)
Mar 29
NOAA 1991–2020 Climate Normals, 28°F — this town
First hard freeze (28°F)
Nov 13
NOAA 1991–2020 Climate Normals, 28°F — this town
Days between freezes
~229
NOAA 1991–2020 Climate Normals, 28°F — this town
Town area
513 acres
US Census TIGER/Line 2025

Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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

7a7a
3a (Cold)13b (Hot)

Zone 7a is Watch Hill's average, not your lot's — a low corner or a tree line moves it. Against Watch Hill's 229-day season, see what your own ground reads.

Soil varies lot by lot — soil types explained.

What this means for growing in Watch Hill

Each reading below is measured for Watch Hill itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length

Measured

Watch Hill runs about 229 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

Measured

Watch Hill 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 Watch Hill is in

Watch Hill sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Watch Hill's own centroid rather than borrowed from Washington County.

What that means for soil

What Grows in Watch Hill

Every plant below cleared Watch Hill's own zone 7a and its 229-day season. Each card opens that plant's Rhode Island profile. How we score.

cabbage, photograph
Growing cabbage in Rhode IslandZones 2–11Watch Hill's 7a — 5 zones of cold margin.
hazelnut, photograph
Rhode Island hazelnut guideZones 4–9Watch Hill's 7a — 3 zones of cold margin.
California poppy, photograph
California poppy in Rhode IslandZones 6–10Watch Hill's 7a — 1 zone of cold margin.
collard greens, photograph
Collard greens: Rhode Island growing notesZones 2–11Watch Hill's 7a — 5 zones of cold margin.
pawpaw, photograph
Growing pawpaw in Rhode IslandZones 5–9Watch Hill's 7a — 2 zones of cold margin.
lavender, photograph
Rhode Island lavender guideZones 5–8Watch Hill's 7a — 2 zones of cold margin.
garlic, photograph
Garlic in Rhode IslandZones 2–10Watch Hill's 7a — 5 zones of cold margin.
pecan, photograph
Pecan: Rhode Island growing notesZones 5–9Watch Hill's 7a — 2 zones of cold margin.
Turkish rocket, photograph
Growing turkish rocket in Rhode IslandWatch Hill's 229 days clear the ~90 it needs.
kale, photograph
Rhode Island kale guideZones 2–11Watch Hill's 7a — 5 zones of cold margin.
prickly pear, photograph
Prickly pear in Rhode IslandZones 5–10Watch Hill's 7a — 2 zones of cold margin.
lentil, photograph
Lentil: Rhode Island growing notesZones 2–11Watch Hill's 229 days clear the ~70 it needs.
apple, photograph
Growing apple in Rhode IslandZones 3–8Watch Hill's 7a — 4 zones of cold margin.
okra, photograph
Rhode Island okra guideZones 2–12Watch Hill's 229 days clear the ~50 it needs.
potato, photograph
Potato in Rhode IslandZones 2–11Watch Hill's 7a — 5 zones of cold margin.
iris, photograph
Iris: Rhode Island growing notesZones 3–10Watch Hill's 7a — 4 zones of cold margin.
sunflower, photograph
Growing sunflower in Rhode IslandZones 2–11Watch Hill's 229 days clear the ~70 it needs.
Apache plume, photograph
Rhode Island apache plume guideZones 5–11Watch Hill's 7a — 2 zones of cold margin.
hops, photograph
Hops in Rhode IslandZones 3–8Watch Hill's 7a — 4 zones of cold margin.
hosta, photograph
Hosta: Rhode Island growing notesZones 3–8Watch Hill's 7a — 4 zones of cold margin.
French marigold, photograph
Growing french marigold in Rhode IslandWatch Hill's 229 days clear the ~50 it needs.
holly, photograph
Rhode Island holly guideZones 5–11Watch Hill's 7a — 2 zones of cold margin.
Virginia creeper, photograph
Virginia creeper in Rhode IslandZones 3–9Watch Hill's 7a — 4 zones of cold margin.
tulip, photograph
Tulip: Rhode Island growing notesZones 6–8Watch Hill's 7a — 1 zone of cold margin.
American elm, photograph
Growing american elm in Rhode IslandZones 3–9Watch Hill's 7a — 4 zones of cold margin.
Ethiopian mustard, photograph
Rhode Island ethiopian mustard guideZones 4–10Watch Hill's 7a — 3 zones of cold margin.
Kentucky bluegrass, botanical illustration
Kentucky bluegrass in Rhode IslandZones 2–7Watch Hill's 7a — 5 zones of cold margin.
Douglas fir, photograph
Douglas fir: Rhode Island growing notesZones 4–10Watch Hill's 7a — 3 zones of cold margin.
Japanese millet, photograph
Growing japanese millet in Rhode IslandZones 5–10Watch Hill's 229 days clear the ~45 it needs.
Eastern gamagrass, photograph
Rhode Island eastern gamagrass guideZones 5–9Watch Hill's 7a — 2 zones of cold margin.

Is it too late to plant in Watch Hill?

For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 13 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.

Documented around Watch Hill

Spotted lanternfly documented 21 miles from Watch Hill, first recorded 2022. What to watch for.

What's on the federal record near Watch Hill

Closest first, within ~10 miles of Watch Hill. Listing isn't leaking, and distance isn't exposure.

  1. ESTATE OF ADELAIDE COHUUnderground Storage Tanks · 450 ft
  2. ANTHONY C. FONDAUnderground Storage Tanks · 750 ft
  3. EUROPEAN IMPORT SERVICEBrownfields · 1600 ft
  4. WATCH HILL GARAGE, INC.Underground Storage Tanks · 1600 ft
  5. WATCH HILL BOAT YARDUnderground Storage Tanks · 2400 ft
  6. OCEAN HOUSEUnderground Storage Tanks · 2600 ft
  7. CHATEAU ST. MICHELE, LTD.Underground Storage Tanks · 0.5 mi
  8. WATCH HILL BOAT YARDBrownfields · 0.6 mi
  9. WATCH HILL FIRE DISTRICTUnderground Storage Tanks · 0.6 mi
  10. WATCH HILL PROPERTIESUnderground Storage Tanks · 0.6 mi
  11. BAY STREET VILLAGE MARKETUnderground Storage Tanks · 0.7 mi
  12. MISQUAMICUT CLUB, THEUnderground Storage Tanks · 0.7 mi

6 more sites are on the record inside the same radius. See them on the map

Measured from Watch Hill'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 Watch Hill.

Total Sites

412

within ~10 miles of Watch Hill

Risk Level

Elevated

Highest-severity

5 Superfund sites (none NPL-listed)

Severity Distribution

within ~10 miles of Watch Hill

High2Moderate103Low307

Highest-Severity Sites

7-Eleven #32509
Underground Storage Tanks · Open UST(S)
Ashaway Line & Twine Manufacturing CO
Toxics Release Inventory · 02804shwyl24lau
Best Way
Underground Storage Tanks · Open UST(S)
Best Way Food & Fuel
Underground Storage Tanks · Open UST(S)
Bestway Hopkinton
Underground Storage Tanks · Open UST(S)

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.
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Check your specific parcel in Watch Hill

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 Watch Hill average

Your land is one point inside Watch Hill

Everything above resolves to Watch Hill as a whole — one PHZM band and one 28°F frost record, read across 513 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 town 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 local average.

Your Lot vs the Watch Hill Average

Watch Hill Average

  • USDA Zones 7a, averaged across Watch Hill
  • One soil character for all of Watch Hill
  • Frost dates read at Watch Hill's scale: Mar 29 to Nov 13

YOUR Parcel

  • Your exact zone, not Watch Hill's 7a
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Watch Hill

Pull a site-specific report for your exact address in Watch Hill, Rhode Island — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your lot that Watch Hill averages can't show:

Your soil pHYour frost-free days — Watch Hill averages 229Your sun & shade

We read public map data around Watch Hill — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Watch Hill average

How we know this about Watch Hill

The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Watch Hill’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.

Common questions about Watch Hill

When does frost risk typically end in Watch Hill?

The last hard freeze (28°F) in Watch Hill typically lands around Mar 29, 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 19.

When is the first frost in Watch Hill?

The first hard freeze (28°F) in Watch Hill typically arrives around Nov 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 30, so the watching starts about Oct 14 — about 229 days after the spring freeze cleared.

How long is the growing season in Watch Hill?

Measured between 28°F hard freezes, Watch Hill sees about 229 frost-free days — roughly Mar 29 through Nov 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 30, about 194 days.

Is the soil safe to grow vegetables in Watch Hill?

The federal record around Watch Hill is a meaningful one — 412 documented sites, mostly Underground Storage Tanks entries (209), the nearest Underground Storage Tanks record under a tenth of a mile 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.

How do I protect my plants from frost in Watch Hill?

From about Oct 14 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 13 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.

Everything above is measured at Watch Hill's scale — its 7a band and its 229-day season. Your yard writes its own version of Watch Hill's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.

What this page reads at Watch Hill’s own scale

7 of the readings below were taken at Watch Hill's own scale — its own ~229-day season between 28°F freezes, the 513 acres it covers and 412 documented sites around it; 4 are borrowed from a wider read, named and linked below.

Measured here

  • Watch Hill's own USDA hardiness band, zones 7aUSDA PHZM 2023
  • Watch Hill's own 28°F hard-freeze dates, about Mar 29 and Nov 13 and the ~229-day span between themNOAA 1991–2020 Climate Normals
  • 412 documented contamination sites on the federal record near Watch Hill, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
  • Watch Hill's boundary and the 513 acres inside itUS Census TIGER/Line 2025
  • Which of 1,086 plants clear zones 7a and a ~229-day seasonGrowable Ground crop-matching engine
  • The ecoregion at Watch Hill's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
  • A documented spotted-lanternfly record within reach of Watch Hilllydemapr (De Bona & Helmus), 10 km survey lattice

Inherited from a wider read

  • Soil character — no town-scale survey exists, so Watch Hill's 513 acres read through its county's SSURGO summaryfrom Washington County
  • Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington County
  • The growing challenges every Rhode Island grower plans around — written at state scale, so they stay on the state guidefrom Rhode Island
  • Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Washington County

What this page can’t tell you

  • The soil pH, drainage, sun hours, and frost pockets on any one lot among Watch Hill's 513 acreswhy one lot differs from the next
  • Which side of Watch Hill you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 513 acresreading your own microclimate
  • How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile out, measured from the town centrehow we read the record
  • Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Watch Hill-wide figureread your own land
The next step finer is your own address