When to plant in Colonial Park, PA
USDA Zone 7aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Colonial Park, Pennsylvania — all computed from Colonial Park's nearest NOAA weather station.
Zone 7a means many perennials and even some tender shrubs overwinter in Colonial Park, while your frost dates still decide when annuals go out.
Frost probability
HARRISBURG 1 NE · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Colonial Park’s own odds, recorded at HARRISBURG 1 NE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 15 | Apr 30 | Apr 14 | Sep 28 | Oct 12 | Oct 28 |
| 32°F | May 2 | Apr 15 | Apr 1 | Oct 7 | Oct 23 | Nov 7 |
| 28°F | Apr 16 | Apr 3 | Mar 19 | Oct 20 | Nov 5 | Nov 21 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Colonial Park, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 12 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Colonial Park planting FAQ
When is the last spring frost in Colonial Park, PA?
On average, the last spring frost in Colonial Park is around April 15 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Colonial Park, PA?
Expect Colonial Park's first fall frost near October 23 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Colonial Park in?
Colonial Park is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Colonial Park?
There are roughly 191 frost-free days in Colonial Park (a moderate growing season), running from the average last frost around April 15 to the first fall frost near October 23.
When should I plant tomatoes in Colonial Park?
In Colonial Park, start tomato seeds indoors around February 18–March 4, then transplant seedlings outdoors around April 22 once the danger of frost has passed.
Never miss a window in Colonial Park
An email when it’s time to start seeds, transplant, and sow — timed to Colonial Park’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Progress · 3 km
- Harrisburg · 7 km
- Hershey · 14 km
- Elizabethtown · 24 km
- Lebanon · 33 km
- Weigelstown · 35 km
- Carlisle · 35 km
- Shiloh · 36 km
Frost dates recorded at HARRISBURG 1 NE, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Colonial Park, PA — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00363698. Retrieved from https://blissgarden.com/pennsylvania/colonial-park.