When to plant in Royal Oak, MI
USDA Zone 6bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Royal Oak, Michigan — all computed from Royal Oak's nearest NOAA weather station.
Heads up: the nearest complete-normals station is about 16 km from Royal Oak, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. Zone 6b means Royal Oak sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
DETROIT CITY 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 Royal Oak’s own odds, recorded at DETROIT CITY AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 18 | May 1 | Apr 19 | Oct 2 | Oct 18 | Oct 31 |
| 32°F | May 6 | Apr 21 | Apr 7 | Oct 17 | Oct 31 | Nov 11 |
| 28°F | Apr 22 | Apr 8 | Mar 27 | Oct 29 | Nov 9 | Nov 23 |
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 Royal Oak, 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.
Royal Oak planting FAQ
When is the last spring frost in Royal Oak, MI?
Plan for the last spring frost in Royal Oak around April 21 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Royal Oak, MI?
The first fall frost in Royal Oak typically arrives around October 31 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Royal Oak in?
Royal Oak 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 Royal Oak?
There are roughly 193 frost-free days in Royal Oak (a moderate growing season), running from the average last frost around April 21 to the first fall frost near October 31.
When should I plant tomatoes in Royal Oak?
In Royal Oak, start tomato seeds indoors around February 24–March 10, then transplant seedlings outdoors around April 28 once the danger of frost has passed.
Never miss a window in Royal Oak
An email when it’s time to start seeds, transplant, and sow — timed to Royal Oak’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Berkley · 3 km
- Clawson · 3 km
- Madison Heights · 4 km
- Oak Park · 5 km
- Ferndale · 6 km
- Birmingham · 7 km
- Hazel Park · 7 km
- Beverly Hills · 7 km
Frost dates recorded at DETROIT CITY AP, 16 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 Royal Oak, MI — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014822. Retrieved from https://blissgarden.com/michigan/royal-oak.