Sterling Heights, Michigan: planting zone & frost dates
Sterling Heights is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around May 5 and the first fall frost around Oct 18.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 15 | Oct 7 |
| Typical planning date (30% risk) | May 5 | Oct 18 |
| Median (50%) | Apr 30 | Oct 24 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station MT CLEMENS ANG BASE, MI (USW00014804), 10.9 mi (17.6 km) from the city center and 36 ft lower than the city center (-11 m). Record used for the 1991–2020 normals: 24 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Sterling Heights
All 4 ZIP codes covering Sterling Heights are in zone 6b.
Vegetable planting calendar for Sterling Heights
Dates are counted from the 30%-risk frost dates above (last frost May 5, first frost Oct 18). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Mar 10 – Mar 24 | May 12 – May 26 | — | — |
| Pepper | Feb 24 – Mar 10 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 24 – Apr 7 | Apr 21 – May 12 | Apr 7 – May 19 | Aug 9 – Sep 6 |
| Green Beans | — | — | May 12 – Jun 16 | Jul 26 – Aug 9 |
| Sweet Corn | — | — | May 12 – Jun 9 | — |
| Zucchini & Summer Squash | Apr 7 – Apr 14 | May 12 – May 26 | May 12 – Jun 2 | Jul 26 – Aug 9 |
| Cucumber | Apr 7 – Apr 14 | May 19 – May 26 | May 12 – Jun 2 | Jul 26 – Aug 9 |
| Carrot | — | — | Apr 14 – May 19 | Jul 26 – Aug 9 |
| Onion | Feb 10 – Feb 24 | Apr 7 – Apr 21 | — | — |
| Potato | — | Apr 7 – Apr 28 | — | — |
| Basil | Mar 24 – Apr 7 | May 19 – Jun 2 | May 19 – Jun 9 | — |
| Spinach | — | — | Mar 24 – Apr 21 | Aug 23 – Sep 20 |
| Kale | Mar 10 – Mar 24 | Apr 7 – Apr 28 | Apr 7 – Apr 28 | Aug 9 – Sep 6 |
| Broccoli | Mar 10 – Mar 24 | Apr 21 – May 12 | — | Jul 26 – Aug 9 |
| Peas | — | — | Mar 24 – Apr 14 | Aug 9 – Aug 23 |
| Eggplant | Feb 24 – Mar 10 | May 19 – Jun 2 | — | — |
| Cabbage | Mar 10 – Mar 24 | Apr 7 – Apr 21 | — | Jul 26 – Aug 9 |
| Radish | — | — | Mar 31 – May 19 | Sep 6 – Oct 4 |
| Strawberry | — | Apr 7 – Apr 28 | — | — |
| Beets | — | — | Apr 14 – May 26 | Aug 9 – Aug 23 |
Nearby cities in Michigan
- Warren — zone 6b, last frost Apr 27, first frost Oct 24
- Troy — zone 6b, last frost May 2, first frost Oct 16
- Rochester Hills — zone 6a, last frost May 2, first frost Oct 16
- Detroit — zone 6b, last frost May 2, first frost Oct 20
- Southfield — zone 6b, last frost May 8, first frost Oct 10
- Dearborn — zone 6b, last frost May 8, first frost Oct 9
More: all Michigan cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY
Sterling Heights gardening questions
When is the last frost in Sterling Heights, MI?
Plan around May 5. At NOAA's Mt Clemens Ang Base, MI station, 10.9 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 30, and after May 15 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 18. The 90% and 10% dates are 29 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Sterling Heights, MI?
Start seeds indoors Mar 10 – Mar 24 and set transplants outside May 12 – May 26, once nights stay above 50°F and the soil is near 60°F. That leaves 166 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Sterling Heights?
About 174 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 153 days, and in 1 year in 10 it runs 192 days or more. In fall there is a 10% chance of frost by Oct 7 and a 30% chance by Oct 18. That ranks 7th longest of 15 Michigan cities on this site.
When should I plant a fall garden in Sterling Heights?
Count back from the first fall frost (Oct 18): transplant broccoli Jul 26 – Aug 9; sow kale Aug 9 – Sep 6; sow lettuce Aug 9 – Sep 6; sow radishes Sep 6 – Oct 4. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 3. How the math works: succession and fall planting.
Did Sterling Heights's hardiness zone change on the 2023 map?
Yes. Most of Sterling Heights was zone 6a on the 2012 map and is zone 6b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does Sterling Heights compare with Troy, MI?
Both are in zone 6b. The typical last spring frost in Sterling Heights (May 5) comes about the same time as in Troy, MI (May 2), 6 miles away, and the first fall frost is Oct 18 versus Oct 16. The two cities use different NOAA stations.