Royal Oak, Michigan planting calendar and frost dates
Royal Oak is in USDA hardiness zone 6b. The last spring frost typically comes around April 21 and the first fall frost around October 31, giving about 190 frost-free days a year.
- Hardiness zone
- Zone 6b
- Typical last frost
- April 21
- Typical first frost
- October 31
- Frost-free season
- 190 days
Frost dates in Royal Oak
Last spring frost
- April 7Risky: frost later than this in 9 years out of 10
- April 21Typical: a later frost in half of years
- May 6Safe: a later frost only 1 year in 10
First fall frost
- October 17Risky: frost earlier than this 1 year in 10
- October 31Typical: an earlier frost in half of years
- November 11Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 190 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around April 8 and returns around November 9.
NOAA U.S. Climate Normals 1991-2020 for Detroit City Airport, 10.9 miles SE of the city center. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers. Royal Oak shares this station with St. Clair Shores, so the two cities have the same frost dates and planting calendar.
What to plant each month in Royal Oak
January
Start indoors: collard greens, leeks, onions, petunias, ranunculus
February
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, kale, leeks, lettuce, marigolds, onions, oregano, parsley, petunias, ranunculus, rosemary, sage, snapdragons
March
Start indoors: basil, black-eyed susans, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, lettuce, marigolds, nasturtiums, peppers, ranunculus, sage, snapdragons, spinach, swiss chard, tomatoes
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, swiss chard, thyme, turnips
May
Start indoors: cosmos, cucumbers, okra, pumpkins, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, ginger, grapes, green beans, green onions, kentucky bluegrass, lavenders, lilies, marigolds, mints, nasturtiums, okra, oregano, parsley, peanuts, peppers, perennial ryegrass, petunias, pumpkins, rosemary, sage, st. augustinegrass, sunflowers, sweet corn, sweet peas, sweet potatoes, tall fescue, thyme, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
June
Plant or sow outdoors: asparagus, bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, sweet potatoes, zinnias, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
Plant for fall: brussels sprouts
August
Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, daylilies, kale, lettuce, peas, radishes, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hydrangeas, kale, lettuce, lilies, ornamental alliums, peonies, radishes, roses, saffron, snapdragons, spinach, tulips, turnips
October
Plant for fall: crocuses, daffodils, daylilies, garlic, grass seed, hostas, hyacinths, kale, lilies, ornamental alliums, peonies, radishes, saffron, tulips
November
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
December
Start indoors: onions
Frost dates and zones by ZIP code in Royal Oak
All 2 of Royal Oak's main ZIP codes take their frost dates from Detroit City Airport, so the dates on this page apply across the city. Every one of them is in zone 6b.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 48067 | 6b | Detroit City Airport, 8.6 mi SE | Apr 21 | Oct 31 |
| 48073 | 6b | Detroit City Airport, 10.9 mi SE | Apr 21 | Oct 31 |
Detroit City Airport also supplies the frost dates for Detroit, Warren, Sterling Heights and St. Clair Shores, so their planting calendars match Royal Oak's.
Planting dates for popular crops in Royal Oak
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 22 to Apr 5 | May 17 to 31 | — |
| Strawberries | — | Mar 10 to 24 | — |
| Lettuce | Feb 24 to Mar 10 | Apr 14 to 28 | Aug 1 to Sep 5 |
| Cilantro | Mar 10 to 24 | Apr 21 to 28 | — |
| Basil | Mar 29 to Apr 12 | May 17 to 24 | — |
| Potatoes | — | Apr 21 to 28 | — |
| Garlic | — | Mar 10 to 24 | Oct 31 to Nov 14 |
| Onions | Dec 30 to Feb 10 | Mar 24 to Apr 7 | — |
| Cucumbers | Apr 19 to May 3 | May 17 to 31 | — |
| Pumpkins | Apr 19 to May 3 | May 17 to 31 | — |
| Peppers | Mar 1 to 29 | May 17 to 31 | — |
| Carrots | — | Mar 31 to Apr 21 | Aug 8 to 29 |
| Sweet Potatoes | — | May 31 to Jun 7 | — |
| Watermelons | Apr 12 to 26 | May 17 to 31 | — |
| Sweet Corn | — | Apr 21 to May 5 | — |
| Green Beans | — | May 17 to 31 | — |
| Zucchini | Apr 19 to May 3 | May 17 to 31 | — |
| Broccoli | Feb 3 to 24 | Mar 24 to Apr 7 | Aug 15 to Sep 12 |
| Peas | — | Mar 10 to 24 | Aug 8 to 22 |
| Spinach | Mar 10 to 17 | Apr 14 to 28 | Aug 22 to Sep 26 |
| Sunflowers | — | Apr 21 to May 12 | — |
| Zinnias | May 19 to 26 | Jun 16 to 30 | — |
| Tulips | — | — | Sep 19 to Nov 14 |
| Daffodils | — | — | Sep 19 to Oct 31 |
| Grass Seed | — | Mar 10 to 24 | Sep 19 to Oct 3 |
Nearby cities
- Troy, MI zone 6b, last frost Apr 26
- Southfield, MI zone 6b, last frost May 1
- Warren, MI zone 6b, last frost Apr 21
- Sterling Heights, MI zone 6b, last frost Apr 21
- Detroit, MI zone 6b, last frost Apr 21
- Rochester Hills, MI zone 6a, last frost Apr 26
Planting in MichiganAbout zone 6bPrintable calendar for Royal Oak
Questions
When is the last frost in Royal Oak?
Around April 21 in a typical year, based on NOAA's 1991-2020 records for Detroit City Airport. There is still a 1 in 10 chance of frost after May 6.
What planting zone is Royal Oak in?
USDA hardiness zone 6b (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Royal Oak?
Start seeds indoors March 22 to April 5 and set plants out May 17 to 31.
When is the first frost in Royal Oak?
Around October 31 in a typical year, and before October 17 about 1 year in 10.