When to plant in Plum, PA
USDA Zone 6bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Plum, Pennsylvania — all computed from Plum's nearest NOAA weather station.
Zone 6b means Plum sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
ACMETONIA LOCK 3 · 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 Plum’s own odds, recorded at ACMETONIA LOCK 3.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 17 | Apr 29 | Apr 13 | Oct 7 | Oct 20 | Nov 1 |
| 32°F | May 4 | Apr 16 | Mar 31 | Oct 18 | Nov 1 | Nov 13 |
| 28°F | Apr 19 | Apr 3 | Mar 19 | Nov 1 | Nov 11 | Nov 25 |
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 Plum, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 13 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.
Plum planting FAQ
When is the last spring frost in Plum, PA?
On average, the last spring frost in Plum is around April 16 (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 Plum, PA?
The first fall frost in Plum typically arrives around November 1 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Plum in?
Plum is in USDA hardiness zone 6b. In zone 6b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Plum?
There are roughly 199 frost-free days in Plum (a moderate growing season), running from the average last frost around April 16 to the first fall frost near November 1.
When should I plant tomatoes in Plum?
In Plum, start tomato seeds indoors around February 19–March 5, then transplant seedlings outdoors around April 23 once the danger of frost has passed.
Never miss a window in Plum
An email when it’s time to start seeds, transplant, and sow — timed to Plum’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- New Kensington · 8 km
- Monroeville · 8 km
- Lower Burrell · 9 km
- Murrysville · 10 km
- Wilkinsburg · 12 km
- Munhall · 18 km
- McKeesport · 20 km
- Allison Park · 20 km
Frost dates recorded at ACMETONIA LOCK 3, 7 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 Plum, PA — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00360022. Retrieved from https://blissgarden.com/pennsylvania/plum.