sweet pea (Lathyrus odoratus), photographi

Can I Grow Sweet Pea in Vermont?

USDA Zones 4a-6a · Plant zone range 2-10

Yes — Strong Match

sweet pea (zones 2-10) covers every zone Vermont contains (4a-6a), so hardiness is not what limits it anywhere in the state.

Sweet Pea in Vermont — the short answer

Sweet Pea in Vermont: hardy in zones 2–10, full sun, against a state median of ~163 frost-free days.

Plant zones
2-10
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
Vermont zones
4a-6a
USDA PHZM 2023
Frost window
Apr 27 - May 5 – Oct 10 - Oct 17
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
146 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
65 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.

Score your parcel · free

Your yard isn't the whole zone.

Sweet Pea is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Vermont site runs ~163 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score sweet pea against your land's actual frost dates, sun, and soil.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Vermont is not one climate

A single Vermont answer averages 14 counties whose growing seasons are 44 days apart — from 146 frost-free days in Essex County to 190 in Grand Isle County. Which end of that your land sits nearer changes what sweet pea can finish before the first hard freeze.

146 daysEssex County190 daysGrand Isle County

The middle half of 14 counties runs 158173 days, with a median of 161 days — a 44-day span end to end.

Measured across 14 Vermont counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Vermont Fits Best

Even within Vermont's zones 4a-6a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for sweet pea (USDA PHZM 2023):

Zone Comparison

Sweet Pea Needs

  • USDA Zones: 2-10
  • Frost-Free Days: 150+
  • Sun: Full Sun
  • Mature size: 6 ft tall
  • Picking window: ~60 days of harvest
  • Drought tolerance: Low

Vermont Has

  • USDA Zones: 4a-6a
  • Last Hard Freeze (28°F): Apr 27 - May 5
  • First Hard Freeze (28°F): Oct 10 - Oct 17
  • Annual Rainfall: 34-44 inches
  • Common Soils: Glacial till, Clay, Silt loam

Plant Zone Range (zones 2-10)

2a
10b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 6.08.0

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 Sweet Pea in Vermont

The frost window

Across Vermont, the last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 158-day window you can count on — up to 173 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.

Frost hardiness

Sweet Pea takes cold down to about 25°F before a freeze kills it (FAO ECOCROP), so you can plant on the early side of Vermont's window — even a few weeks before the final hard freeze. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.

When to start the seed

Those dates are when sweet pea goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from Vermont's late-side last freeze of May 5 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 65 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 93 days to spare even in Vermont'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 sweet pea survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Sweet Pea wants 150+ frost-free days; a typical Vermont site sees ~163 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a tight window — use transplants and pick early-maturing cultivars.

Growing degree days

Sweet Pea needs ~500 GDD (base 50°F) to ripen. The state median runs ~1746 GDD (from PRISM 1991-2020 climate normals), so Vermont's typical season clears that easily.

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

Sweet Pea likes near-neutral soil (pH 6-8). That's the common-ground band across Vermont's glacial till and clay — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6.5 and 7.5 — worth knowing before you decide whether a Vermont soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Vermont 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. Vermont soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Sweet Pea in Vermont

Zone compatibility tells you about winter cold survival — but Vermont growers also need to think about:

Short growing season (100-130 frost-free days)

Rocky soils throughout the Green Mountains

Heavy clay in the Champlain Valley

What to actually do about these — and the constraints that apply to every Vermont grower, not just sweet pea — is covered on the Vermont growing guide.

Timing shifts within Vermont

Sweet Pea needs about 150 days of frost-free season to complete its cycle. 13 of Vermont’s 14 counties give it that outright. The tightest that does is Caledonia County at 153 frost-free days — 3 to spare. Below that line you are transplanting or extending the season, not direct-sowing.

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"). Sweet Pea's 150-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

Sweet Pea draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, sweet pea can only work that bloom inside Vermont's frost window — roughly 163 days, opening after the last 28°F freeze (Apr 27 - May 5) and closing at the first (Oct 10 - Oct 17), per NOAA Regional Climate Centers ACIS, 1991-2020.

Vermont Cooperative Extension

For Vermont-specific cultivar recommendations, planting calendars, and pest pressure for sweet pea, the canonical source is UVM Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Sweet Pea native to Vermont?

No — the USDA PLANTS Database lists Sweet Pea as introduced rather than native in the Lower 48, so it is not part of Vermont's native flora. It grows here as a garden plant; pairing it with a few Vermont natives keeps local pollinators fed too.

Looking for plants that belong here? The Vermont growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Sweet Pea in Vermont

When can I plant Sweet Pea in Vermont?

Vermont's last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Sweet Pea takes cold to about 25°F before a freeze kills it (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor), so plant on the early side of that window — even ahead of the final hard freeze.

Can Sweet Pea mature before first frost in Vermont?

Yes — Sweet Pea matures in 65 days (Growable Ground Plant Database), and Vermont's dependable hard-freeze-free window runs 158 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 93 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 Sweet Pea grown in across Vermont?

Vermont spans USDA hardiness zones 4a-6a (USDA ARS PHZM 2023). Sweet Pea carries a range of zones 2-10, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Vermont site have?

A typical Vermont site sees ~163 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Sweet Pea needs 150+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Sweet Pea native to Vermont?

No — the USDA PLANTS Database lists Sweet Pea as introduced rather than native in the Lower 48, so it is not part of Vermont's native flora. It grows here as a garden plant; pairing it with a few Vermont natives keeps local pollinators fed too.

How should I amend the soil for Sweet Pea in Vermont?

Sweet Pea prefers pH 6-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Vermont soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Sweet Pea actually grow on my specific land in Vermont?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores sweet pea against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Vermont

State-level data is a sketch. Your Growable Ground report scores sweet pea against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Vermont sweet pea averages can't show:

Your soil pHYour frost-free days — Vermont averages 163Your sun & shade

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

25+ data sources read at your address, not the Vermont sweet pea average

Explore More

Explore Vermont county by county

Vermont carries 14 counties with their own USDA zone — a sample of the growing pages for sweet pea there:

Where else sweet pea grows

Sweet Pea's zone band crosses state lines — these are the states closest to Vermont 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 Vermont

Vermont has a growing page for 747 plants — a rotating sample of the rest of the shelf.

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