When to plant in Plymouth, MN
USDA Zone 5aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Plymouth, Minnesota — all computed from Plymouth's nearest NOAA weather station.
Zone 5a means Plymouth sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
The average first fall frost in Plymouth is now 5 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
NEW HOPE · 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 Plymouth’s own odds, recorded at NEW HOPE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 23 | May 8 | Apr 26 | Sep 19 | Oct 1 | Oct 14 |
| 32°F | May 12 | Apr 29 | Apr 15 | Sep 29 | Oct 12 | Oct 25 |
| 28°F | May 1 | Apr 19 | Apr 5 | Oct 8 | Oct 22 | Nov 4 |
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 Plymouth, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 18 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.
Plymouth planting FAQ
When is the last spring frost in Plymouth, MN?
Plymouth's average last spring frost falls near April 29 — 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 Plymouth, MN?
The first fall frost in Plymouth typically arrives around October 12 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Plymouth in?
Plymouth is in USDA hardiness zone 5a. In zone 5a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Plymouth?
There are roughly 166 frost-free days in Plymouth (a moderate growing season), running from the average last frost around April 29 to the first fall frost near October 12.
When should I plant tomatoes in Plymouth?
In Plymouth, start tomato seeds indoors around March 4–March 18, then transplant seedlings outdoors around May 6 once the danger of frost has passed.
Never miss a window in Plymouth
An email when it’s time to start seeds, transplant, and sow — timed to Plymouth’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- New Hope · 6 km
- Crystal · 8 km
- Golden Valley · 9 km
- Minnetonka · 10 km
- Maple Grove · 10 km
- Robbinsdale · 10 km
- St. Louis Park · 11 km
- Hopkins · 12 km
Frost dates recorded at NEW HOPE, 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 Plymouth, MN — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00215838. Retrieved from https://blissgarden.com/minnesota/plymouth.