When to plant in Trenton, MI
USDA Zone 6bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Trenton, Michigan — all computed from Trenton's nearest NOAA weather station.
Trenton's nearest full-normals station sits about 15 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. In zone 6b, Trenton gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
DETROIT METRO AP · 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 Trenton’s own odds, recorded at DETROIT METRO AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 18 | May 2 | Apr 18 | Oct 2 | Oct 15 | Oct 29 |
| 32°F | May 8 | Apr 20 | Apr 6 | Oct 14 | Oct 27 | Nov 9 |
| 28°F | Apr 24 | Apr 8 | Mar 27 | Oct 27 | Nov 7 | Nov 22 |
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 Trenton, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 22 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.
Trenton planting FAQ
When is the last spring frost in Trenton, MI?
Trenton's average last spring frost falls near April 20 — 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 Trenton, MI?
In Trenton, the first 32°F freeze of fall lands around October 27 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Trenton in?
Trenton 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 Trenton?
Trenton has about 190 frost-free days — a moderate growing season — between the average last spring frost (April 20) and first fall frost (October 27).
When should I plant tomatoes in Trenton?
For Trenton, sow tomatoes indoors about February 23–March 9 and move the seedlings out around April 27, after the last spring frost.
Never miss a window in Trenton
An email when it’s time to start seeds, transplant, and sow — timed to Trenton’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Woodhaven · 4 km
- Riverview · 4 km
- Southgate · 7 km
- Flat Rock · 8 km
- Wyandotte · 8 km
- Taylor · 11 km
- Lincoln Park · 12 km
- Allen Park · 13 km
Frost dates recorded at DETROIT METRO AP, 15 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 Trenton, MI — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094847. Retrieved from https://blissgarden.com/michigan/trenton.