Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 05735 — Castleton, VT

ZIP code 05735 (Castleton, Rutland County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 15 and the first fall frost September 27.

Where ZIP 05735 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone5a−20 to −15 °F

Coldest night−28.9 to −26.1 °C

Last frostMay 15

First frostSep 27

2012 zone5a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Castleton, VT…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Castleton, VT

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 15median — 50% chance of a later frost

Safe for tender plantsMay 31only 10% chance of frost after

First fall frostSeptember 27median — 10% chance by Sep 13

Growing season132 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 5.

From the NOAA station Rutland, VT — 9 miles away, elevation 620 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 05735

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 3 – Apr 17

SpinachSow outdoors · Apr 3 – Apr 24

Broccoli, cabbageStart indoors · Mar 6 – Mar 20

Broccoli, cabbageTransplant · Apr 24 – May 8

Onion setsPlant outdoors · Apr 17 – May 1

PotatoesPlant outdoors · Apr 24 – May 8

LettuceSow outdoors · Apr 17 – May 1

Carrots, beetsSow outdoors · Apr 24 – May 8

TomatoesStart indoors · Mar 20 – Apr 3

TomatoesTransplant · May 22 – Jun 5

Peppers, eggplantStart indoors · Mar 6 – Mar 20

Peppers, eggplantTransplant · May 29 – Jun 12

BeansSow outdoors · May 22 – Jun 5

Sweet cornSow outdoors · May 22 – Jun 5

Cucumbers, squashSow outdoors · May 22 – Jun 5

Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16

GarlicPlant cloves · Sep 13 – Oct 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 15) and first fall frost (Sep 27) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 05735 came on Apr 16 — 3 days earlier than the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 16

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in Castleton, VT

The soil mapped at the center of ZIP 05735 is Taconic — very channery silt loam, somewhat excessively drained.

TextureVery channery silt loama good balance for most vegetables

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter4%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Taconic-Hubbardton complex, 8 to 25 percent slopes, very rocky.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 05735; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Castleton, VT

Summer high80 °Faverage high, July

Winter low8 °Faverage low, January

Hot days4days a year at 90 °F or more

Freezing nights164nights a year at 32 °F or less

Growing degree days2,056base 50 °F — the season’s usable heat

Longest day15 h 27 mindaylight on June 21

Shortest day8 h 55 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation44.8 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Rutland, VT (9 mi away); precipitation: West Rutland 1.2 N, VT (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

Fair Haven, VT · 7 mi

057365a

Center Rutland, VT · 8 mi

057775a

West Rutland, VT · 9 mi

057645a

Poultney, VT · 9 mi

Vermont planting zones →

Questions about 05735

What planting zone is ZIP code 05735?

ZIP code 05735 (Castleton, VT) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Castleton, VT?

The median last spring frost (32 °F) near 05735 is May 15; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Rutland station.

When is the first frost in Castleton, VT?

The median first fall frost near 05735 is September 27, giving a median frost-free growing season of 132 days.

When should I plant tomatoes in 05735?

Start tomato seeds indoors around Mar 20 – Apr 3 and set transplants outside around May 22 – Jun 5, one to three weeks after the median last frost.

How much rain and snow does 05735 get?

About 44.8 inches of precipitation a year (NOAA 1991–2020 normals, West Rutland 1.2 N station).

How hot do summers get in Castleton, VT?

The average high peaks at 80 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 05735 have?

The USDA soil survey maps Taconic at the center of ZIP 05735: very channery silt loam, somewhat excessively drained, pH about 5.3 (strongly acidic).

Did spring come early in Castleton, VT in 2026?

Spring leaf-out near 05735 came on Apr 16 in 2026, 3 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Castleton, VT?

Long-day onions: the longest day near 05735 is 15 h 27 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).