Yes — Strong Match
Hubbard squash (zones 2-11) covers every zone Rhode Island contains (6b-7b), so hardiness is not what limits it anywhere in the state.
Hubbard Squash in Rhode Island — the short answer
Hubbard Squash in Rhode Island: hardy in zones 2–11, full sun, against a state median of ~225 frost-free days.
- Plant zones
- 2-11
- 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
- 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
- Days to maturity
- 100 days
- Growable Ground Plant Database
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 has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score hubbard squash against your land's actual soil, sun, and frost.
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Where in Rhode Island Fits Best
Even within Rhode Island's zones 6b-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for hubbard squash (USDA PHZM 2023):
Zone Comparison
Hubbard Squash Needs
- USDA Zones: 2-11
- Frost-Free Days: 80+
- Sun: Full Sun
- Mature size: 2 ft tall
- Picking window: ~18 days of harvest
- Drought tolerance: Low
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 2-11)
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 Hubbard Squash 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.
When to start the seed
Those dates are when hubbard squash goes out, not when it starts. It is sown under cover about 3 weeks ahead, so counting back from Rhode Island's late-side last freeze of Apr 3 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 100 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 118 days to spare even in Rhode Island's tightest freeze scenario — room for a later start or a second sowing.
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 hubbard squash survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Hubbard Squash wants 80+ frost-free days; a typical Rhode Island site sees ~225 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Hubbard Squash needs ~2200 GDD (base 50°F) to ripen. The state median runs ~2635 GDD (from PRISM 1991-2020 climate normals), so Rhode Island sits right at the threshold — pay attention to siting and microclimate.
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
Hubbard Squash tolerates a wide pH range (pH 5-8.5) — 3.5 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 7.5 — worth knowing before you decide whether a Rhode Island soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Rhode Island site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
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.
Before you plant hubbard squash for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before hubbard squash goes in. What follows is Rhode Island’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
Safe to Grow Here?
What the federal record shows across Rhode Island — and how to grow with it.
We checked the federal record across Rhode Island — 7,250 documented sites across 7 of the 9 source types we track.
The most significant on record: 141 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Rhode Island carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources Checked
across Rhode Island
Severity Distribution
across Rhode Island
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rhode Island, two things run higher than the national average across Rhode Island — Superfund (141 sites) and Toxics Release Inventory (446 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What Else to Consider for Hubbard Squash 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
What to actually do about these — and the constraints that apply to every Rhode Island grower, not just hubbard squash — is covered on the Rhode Island growing guide.
Timing shifts within Rhode Island
Hubbard Squash needs about 80 days of frost-free season to complete its cycle. Even Providence County — Rhode Island’s shortest season at 210 frost-free days — clears that by 130 days, so season length isn’t the constraint anywhere in Rhode Island. What varies is your own parcel.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Hubbard Squash's 80-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Hubbard Squash draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, hubbard squash 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.
Rhode Island Cooperative Extension
For Rhode Island-specific cultivar recommendations, planting calendars, and pest pressure for hubbard squash, the canonical source is URI Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Hubbard Squash native to Rhode Island?
No — the USDA PLANTS Database lists Hubbard Squash as introduced rather than native in the Lower 48, so it is not part of Rhode Island's native flora. It grows here as a garden plant; pairing it with a few Rhode Island natives keeps local pollinators fed too.
Looking for plants that belong here? The Rhode Island growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
What pests threaten hubbard squash in Rhode Island?
Squash bug and squash vine borer are documented in Rhode Island, and they hit hubbard squash where it counts. Here is what each one actually does — and the move that beats it.
Squash bug
Act on thisSquash bugs primarily attack squash and pumpkins, and the plants most at risk are the youngest and the ones in flower — the University of Minnesota notes feeding can kill young plants outright, while a larger, sturdier plant shrugs it off.
What to do: Go after where they sleep, not just the bugs. Crush the bronze egg clusters on the leaf undersides in the vein angles, drop nymphs and adults into soapy water, and clear plant debris through the season and again in fall to strip out overwintering shelter. Where squash bugs are a consistent problem, skip straw mulch — it gives them the night shelter they are looking for.
Here: In Rhode Island that second clean-up lands around Nov 7 - Nov 21, when the first 28°F freeze typically ends the hubbard squash — pulling the vines then is what strips the overwintering shelter, and leaving them is what stocks next season.
Documented range: the United States · University of Minnesota Extension, University of Illinois IPM, University of Kentucky Entomology
Squash vine borer
Act on thisThe wilt you notice is the larva already inside the stem. The University of Illinois puts it plainly: the squash vine borer cannot complete its development except in squash or pumpkins — and Hubbard and acorn types are the ones Kentucky and Wisconsin name as most susceptible.
What to do: Two moves beat it, and both are about timing. Float a row cover over the plants when the vines start to run — late June or early July for non-vining types — anchor the sides, and keep it on for about two weeks after the first adult moth is seen; take it off once flowers open so bees can work. Then sow a second planting of summer squash in early July: those plants mature after the moths have finished laying and come through undamaged.
Here: The escape works here. Rhode Island's ~225 frost-free days carry two ~100-day hubbard squash crops, so a later sowing has room to finish after the moths have stopped laying.
Documented range: the United States east of the Rocky Mountains · University of Minnesota Extension, University of Wisconsin–Madison Division of Extension, University of Kentucky Entomology, University of Illinois IPM
Only pests whose documented range and host relationship both trace to a primary source appear here — so a quiet section means we have nothing sourced to tell you, not that your garden is pest-free.
Common Questions About Growing Hubbard Squash in Rhode Island
When can I plant Hubbard Squash 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). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
Can Hubbard Squash mature before first frost in Rhode Island?
Yes — Hubbard Squash matures in 100 days (Growable Ground Plant Database), and Rhode Island's dependable hard-freeze-free window runs 218 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 118 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Hubbard Squash grown in across Rhode Island?
Rhode Island spans USDA hardiness zones 6b-7b (USDA ARS PHZM 2023). Hubbard Squash carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.
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). Hubbard Squash needs 80+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Hubbard Squash native to Rhode Island?
No — the USDA PLANTS Database lists Hubbard Squash as introduced rather than native in the Lower 48, so it is not part of Rhode Island's native flora. It grows here as a garden plant; pairing it with a few Rhode Island natives keeps local pollinators fed too.
How should I amend the soil for Hubbard Squash in Rhode Island?
Hubbard Squash tolerates pH 5-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 3.5-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 Hubbard Squash actually grow on my specific land in Rhode Island?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores hubbard squash 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 Rhode Island
State-level data is a sketch. Your Growable Ground report scores hubbard squash against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Rhode Island hubbard squash 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 hubbard squash average
Explore More
Growing guides for hubbard squash
Explore Rhode Island county by county
Rhode Island carries 5 counties with their own USDA zone — a sample of the growing pages for hubbard squash there:
Where else hubbard squash grows
Hubbard Squash'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 889 plants — a rotating sample of the rest of the shelf.
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