When to plant in Mercerville, NJ
USDA Zone 7aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Mercerville, New Jersey — all computed from Mercerville's nearest NOAA weather station.
In zone 7a, Mercerville supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
TRENTON STATE COLLEGE · 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 Mercerville’s own odds, recorded at TRENTON STATE COLLEGE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 17 | May 1 | Apr 16 | Oct 1 | Oct 15 | Oct 30 |
| 32°F | May 6 | Apr 17 | Apr 2 | Oct 11 | Oct 28 | Nov 10 |
| 28°F | Apr 17 | Apr 2 | Mar 18 | Oct 25 | Nov 7 | Nov 24 |
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 Mercerville, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 11 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.
Mercerville planting FAQ
When is the last spring frost in Mercerville, NJ?
On average, the last spring frost in Mercerville is around April 17 (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 Mercerville, NJ?
The first fall frost in Mercerville typically arrives around October 28 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Mercerville in?
Mercerville 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 Mercerville?
Mercerville has about 194 frost-free days — a moderate growing season — between the average last spring frost (April 17) and first fall frost (October 28).
When should I plant tomatoes in Mercerville?
For Mercerville, sow tomatoes indoors about February 20–March 6 and move the seedlings out around April 24, after the last spring frost.
Never miss a window in Mercerville
An email when it’s time to start seeds, transplant, and sow — timed to Mercerville’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Hamilton Square · 4 km
- White Horse · 5 km
- Trenton · 6 km
- Princeton · 14 km
- Princeton Meadows · 15 km
- Levittown · 16 km
- Kendall Park · 23 km
- Franklin Park · 26 km
Frost dates recorded at TRENTON STATE COLLEGE, 9 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 Mercerville, NJ — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00288880. Retrieved from https://blissgarden.com/new-jersey/mercerville.