USDA zone 4b in Vermont
USDA plant hardiness zone 4b covers 13 locations across Vermont (average annual extreme minimum −25 to −20 °F): East Burke, VT, Enosburg Falls, VT, Glover, VT, Greensboro, VT, Groton, VT, Lowell, VT, and 7 more. Average last spring frost across this group ranges May 9 (Sheffield) to June 1 (Sutton), and growing seasons run 103–143 days (Sutton to St. Johnsbury) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Vermont location's own frost dates; the printable planting calendar uses South Barre, this group's median-season location.
- USDA zone
- 4b−25 to −20 °F
- Last frost range
- May 9–Jun 1avg, 32°F
- First frost range
- Sep 13–Oct 3avg, 32°F
- Growing season range
- 103–143days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| East Burke | — | N Stratford | May 19 | Sep 29 | 131 |
| Enosburg Falls | Richford, Bakersfield | Enosburg Falls | May 14 | Oct 1 | 139 |
| Glover | Orleans, West Burke | Island Pond | May 19 | Sep 29 | 129 |
| Greensboro | Morrisville, Hardwick, Albany, Hyde Park, Wolcott | Morrisville Stowe State Ap | May 20 | Sep 28 | 129 |
| Groton | Hardwick, Peacham, Cabot, Plainfield, Marshfield, East Montpelier | Plainfield | May 25 | Sep 22 | 119 |
| Lowell | North Troy | Jay Peak | May 14 | Oct 1 | 138 |
| Newport | Glover, Albany, Barton, Irasburg, Newport Center, Coventry | Newport | May 14 | Sep 30 | 138 |
| Quechee | — | Woodstock | May 13 | Oct 1 | 141 |
| Sheffield | — | Sutton | May 9 | Oct 1 | 143 |
| South Barre * | — | Barre Montpelier Ap | May 16 | Sep 29 | 136 |
| St. Johnsbury | Greensboro Bend, Peacham, Concord, Danville, Barnet, East Burke, +1 more | Saint Johnsbury | May 13 | Oct 3 | 143 |
| Sutton | — | Sutton 2ne | Jun 1 | Sep 13 | 103 |
| Wells River | — | Benton 5 Sw | May 15 | Sep 28 | 133 |
* South Barre is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (South Barre, representative)
Computed from South Barre's average frost dates — the median-season location in this Vermontzone 4b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 21 – Apr 4 | May 23 – May 30 | Jul 22 – Aug 11 | — | matures comfortably |
| Pepper | Very tender | Mar 7 – Mar 21 | May 30 – Jun 6 | Jul 29 – Aug 28 | — | matures comfortably |
| Cucumber | Tender | Apr 18 – Apr 25 | May 23 – May 30 | Jul 12 – Aug 1 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 23 – May 30 | Jul 7 – Jul 22 | — | matures comfortably |
| Bush bean | Tender | — | May 23 – May 30 | Jul 12 – Jul 22 | Jul 31 – Aug 10 | matures comfortably |
| Sweet corn | Tender | — | May 16 – May 30 | Jul 15 – Aug 14 | — | matures comfortably |
| Basil | Very tender | Apr 4 – Apr 18 | May 23 – May 30 | Jun 22 – Jul 7 | — | matures comfortably |
| Lettuce | Half-hardy | Apr 4 – Apr 18 | Apr 18 – May 2 | Jun 2 – Jun 17 | Jul 17 – Aug 1 | matures comfortably |
| Pea | Hardy | — | Apr 4 – Apr 18 | May 29 – Jun 13 | Jul 7 – Jul 22 | matures comfortably |
| Spinach | Hardy | — | Apr 4 – Apr 18 | May 14 – May 24 | Jul 27 – Aug 6 | matures comfortably |
| Carrot | Half-hardy | — | Apr 25 – May 2 | Jun 24 – Jul 14 | Jun 27 – Jul 17 | matures comfortably |
| Broccoli | Half-hardy | Mar 21 – Apr 4 | Apr 18 – May 2 | Jun 12 – Jul 2 | Jul 2 – Jul 22 | matures comfortably |
Which crops fit this growing season
Using South Barre's own 136-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (South Barre)
From NOAA's 1991–2020 Climate Normals at station USW00094705. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 30 | Jun 12 | Sep 20 | Oct 2 | 112 |
| 32°F (freeze) | May 16 | May 30 | Sep 29 | Oct 12 | 136 |
| 28°F | May 3 | May 17 | Oct 9 | Oct 26 | 158 |
| 24°F | Apr 21 | May 4 | Oct 22 | Nov 7 | 184 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 13 locations is 1,821; South Barre's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 1,821 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 3,596 | cool-season crops (brassicas, greens) |
Hardiness zone 4b in Vermont
Zone 4b means an average annual extreme minimum winter temperature of about −25 to −20 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Vermont spans 4 hardiness zones in this dataset — see all Vermont locations for the full range, including zones4a, 5a, 5b.
Explore zone 4b in other states at zone 4b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 4b mean in Vermont?
- Zone 4b means an average annual extreme minimum winter temperature of −25 to −20 °F — the standard USDA measure of which perennials survive winter. 13 locations in Vermont fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Vermont's zone 4b is the growing season longest?
- St. Johnsbury runs the longest season on this page at about 143 days; Sutton is shortest at about 103 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Vermont's zone 4b?
- Using South Barre's frost dates (this page's median-season location): start seeds indoors about Mar 21 – Apr 4, then transplant outside about May 23 – May 30. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Vermont's zone 4b have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 13 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.