When to plant in Roslyn, PA
USDA Zone 7bEverything below — frost dates, hardiness zone, and what to plant when in Roslyn, Pennsylvania — is derived from the closest NOAA station with complete climate normals.
Zone 7b means many perennials and even some tender shrubs overwinter in Roslyn, while your frost dates still decide when annuals go out.
Frost probability
WILLOW GROVE NAS · 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 Roslyn’s own odds, recorded at WILLOW GROVE NAS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 11 | Apr 24 | Apr 10 | Oct 6 | Oct 21 | Nov 4 |
| 32°F | Apr 27 | Apr 11 | Mar 29 | Oct 17 | Nov 1 | Nov 17 |
| 28°F | Apr 12 | Mar 30 | Mar 15 | Nov 1 | Nov 13 | Dec 1 |
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 Roslyn, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 16 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.
Roslyn planting FAQ
When is the last spring frost in Roslyn, PA?
Roslyn's average last spring frost falls near April 11 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Roslyn, PA?
In Roslyn, the first 32°F freeze of fall lands around November 1 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Roslyn in?
Roslyn is in USDA hardiness zone 7b. In zone 7b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Roslyn?
There are roughly 204 frost-free days in Roslyn (a moderate growing season), running from the average last frost around April 11 to the first fall frost near November 1.
When should I plant tomatoes in Roslyn?
In Roslyn, start tomato seeds indoors around February 14–February 28, then transplant seedlings outdoors around April 18 once the danger of frost has passed.
Never miss a window in Roslyn
An email when it’s time to start seeds, transplant, and sow — timed to Roslyn’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Willow Grove · 3 km
- Horsham · 6 km
- Philadelphia · 14 km
- Bala Cynwyd · 15 km
- Montgomeryville · 16 km
- Norristown · 17 km
- Lansdale · 17 km
- Ardmore · 20 km
Frost dates recorded at WILLOW GROVE NAS, 8 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 Roslyn, PA — Frost Dates & Zone 7b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014793. Retrieved from https://blissgarden.com/pennsylvania/roslyn.