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

Planting zone for Valley Forge, PA

Valley Forge, PA is in USDA zone 7a across its 7 ZIP codes. The median last spring frost is April 18 and the first fall frost October 27.

Valley Forge on the zone map

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.

Zone7a0 to 5 °F
ZIP codes7
Last frostApr 18
First frostOct 27
Growing season192 days

7a 7 ZIPs

Frost forecast — next 7 nights

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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 Valley Forge, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 4only 10% chance of frost after
First fall frostOctober 27median — 10% chance by Oct 12
Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 3 and returns around November 6.

From the NOAA station Phoenixville 1 E, PA, elevation 85 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 Valley Forge

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Sep 1 – Sep 15
GarlicPlant cloves · Oct 13 – Nov 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 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 19481 came on Mar 22 — 3 days earlier than the 1991–2020 average (Mar 25).

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).

Native plants for zone 7a in Pennsylvania

620 plants native to the lower 48 states, recorded in Pennsylvania, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 78

Shrubs 123

Wildflowers & perennials 212

Grasses 181

Vines 11

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Valley Forge, PA.

Soil in Valley Forge, PA

The soil mapped at the center of ZIP 19481 is Edgemont — channery loam, well drained.

TextureChannery loama good balance for most vegetables
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Edgemont channery loam, 15 to 25 percent slopes.

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 19481; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Valley Forge, PA

Summer high88 °Faverage high, July
Winter low23 °Faverage low, January
Hot days29days a year at 90 °F or more
Freezing nights117nights a year at 32 °F or less
Growing degree days3,668base 50 °F — the season’s usable heat
Longest day15 h 02 mindaylight on June 21
Shortest day9 h 19 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.1 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 41 °F, low 23 °F 41°23° JanFebruary: average high 44 °F, low 24 °F 44°24° FebMarch: average high 53 °F, low 31 °F 53°31° MarApril: average high 65 °F, low 41 °F 65°41° AprMay: average high 75 °F, low 51 °F 75°51° MayJune: average high 83 °F, low 61 °F 83°61° JunJuly: average high 88 °F, low 66 °F 88°66° JulAugust: average high 86 °F, low 64 °F 86°64° AugSeptember: average high 79 °F, low 56 °F 79°56° SepOctober: average high 67 °F, low 44 °F 67°44° OctNovember: average high 56 °F, low 34 °F 56°34° NovDecember: average high 45 °F, low 27 °F 45°27° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.15 in precipitation 3.1 JanFebruary: 2.87 in precipitation 2.9 FebMarch: 3.67 in precipitation 3.7 MarApril: 3.52 in precipitation 3.5 AprMay: 3.30 in precipitation 3.3 MayJune: 3.85 in precipitation 3.9 JunJuly: 4.57 in precipitation 4.6 JulAugust: 4.37 in precipitation 4.4 AugSeptember: 4.43 in precipitation 4.4 SepOctober: 3.91 in precipitation 3.9 OctNovember: 3.41 in precipitation 3.4 NovDecember: 4.08 in precipitation 4.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Phoenixville 1 E, PA (3 mi away); precipitation: Phoenixville 1 E, PA (3 mi away). Daylight is calculated from latitude.

ZIP codes in Valley Forge

Pennsylvania planting zones →

Questions about Valley Forge

What planting zone is Valley Forge, PA?

Valley Forge, PA is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Valley Forge, PA?

The median last spring frost is April 18 and the median first fall frost is October 27 (NOAA 1991–2020 normals, Phoenixville 1 E station).

When can I plant a garden in Valley Forge, PA?

Cool-season crops like peas and spinach go in around Mar 7 – Mar 28; tomatoes, peppers, beans and squash after about Apr 25, once frost risk has passed.

What kind of onions grow in Valley Forge, PA?

Long-day onions: the longest day is 15 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Valley Forge, PA get?

About 45.1 inches of precipitation a year (NOAA 1991–2020 normals).