When to plant in Romulus, MI
USDA Zone 6bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Romulus, Michigan — all computed from Romulus's nearest NOAA weather station.
Zone 6b means Romulus sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
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 Romulus’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 Romulus, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Romulus planting FAQ
When is the last spring frost in Romulus, MI?
On average, the last spring frost in Romulus is around April 20 (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 Romulus, MI?
The first fall frost in Romulus typically arrives around October 27 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Romulus in?
Romulus 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 Romulus?
There are roughly 190 frost-free days in Romulus (a moderate growing season), running from the average last frost around April 20 to the first fall frost near October 27.
When should I plant tomatoes in Romulus?
In Romulus, start tomato seeds indoors around February 23–March 9, then transplant seedlings outdoors around April 27 once the danger of frost has passed.
Never miss a window in Romulus
An email when it’s time to start seeds, transplant, and sow — timed to Romulus’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Wayne · 6 km
- Taylor · 8 km
- Inkster · 9 km
- Westland · 11 km
- Garden City · 11 km
- Southgate · 13 km
- Allen Park · 13 km
- Dearborn Heights · 14 km
Frost dates recorded at DETROIT METRO AP, 3 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 Romulus, MI — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094847. Retrieved from https://blissgarden.com/michigan/romulus.