Frost Dates for Rockwood, MI 48173
Last spring frost April 26 · First fall frost October 17 · 174 frost-free days · USDA Zone 6b
ZIP 48173 has about 12,900 people.
Moderate season: 174 frost-free days. Spring frost risk spans April 11–May 10 (29 days). Fall frost risk spans October 4–October 30 (26 days).
Frost probability for 48173
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 10 | April 26 | April 11 |
| Fall (first frost) | October 4 | October 17 | October 30 |
Dates come from NOAA 1971–2000 freeze probabilities at DETROIT METRO AP (19.7 km away); the 50% date is the median year.
Which crops fit a 174-day season in Rockwood
In Rockwood (174 frost-free days, a moderate season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 22 | May 10–May 17 | 132 | fits: 80 days to maturity, 132 available after May 10. | Jun 17 |
| Pepper | Mar 15 | May 10–May 17 | 132 | fits: 75 days to maturity, 132 available after May 10. | Jun 22 |
| Lettuce | Mar 1 | Mar 29–Apr 5 | 209 | two-plantings: Plant Mar 29 and again by Aug 26; both mature before Oct 24. | Aug 26 |
| Carrots | — | Apr 5–Apr 12 | 216 | fits: 70 days to maturity, 216 available after Apr 5. | Aug 15 |
| Cucumber | Apr 5 | May 10–May 17 | 146 | two-plantings: Plant May 10 and again by Jul 21; both mature before Oct 3. | Jul 21 |
| Beans | — | May 3–May 17 | 160 | two-plantings: Plant May 3 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Peas | — | Mar 1–May 10 | 237 | fits: 65 days to maturity, 237 available after Mar 1. | Aug 6 |
| Zucchini | Apr 12 | May 10–May 17 | 146 | two-plantings: Plant May 10 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Onion | Feb 1 | Mar 29–Apr 12 | 209 | fits: 100 days to maturity, 209 available after Mar 29. | — |
| Spinach | — | Mar 1–Apr 19 | 251 | two-plantings: Plant Mar 1 and again by Sep 14; both mature before Nov 7. | Sep 14 |
| Kale | Feb 15 | Mar 29–Apr 12 | 223 | two-plantings: Plant Mar 29 and again by Aug 30; both mature before Nov 7. | Aug 30 |
| Broccoli | Mar 1 | Mar 29–Apr 12 | 209 | fits: 80 days to maturity, 209 available after Mar 29. | Jul 22 |
| Cabbage | Mar 1 | Mar 29–Apr 12 | 223 | fits: 70 days to maturity, 223 available after Mar 29. | Aug 15 |
| Radish | — | Mar 1–May 24 | 237 | two-plantings: Plant Mar 1 and again by Sep 15; both mature before Oct 24. | Sep 15 |
| Beets | — | Mar 1–May 24 | 237 | two-plantings: Plant Mar 1 and again by Aug 16; both mature before Oct 24. | Aug 16 |
| Potatoes | — | Apr 12–Apr 19 | 195 | fits: 90 days to maturity, 195 available after Apr 12. | — |
| Garlic | — | Oct 17 | 279 | overwinter: Plant Oct 17 to Nov 7; harvest the following summer. | Nov 7 |
| Strawberry | — | Mar 22–May 17 | 230 | perennial: A perennial: plant Mar 22; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 29 | May 3–May 10 | 146 | fits: 75 days to maturity, 146 available after May 3. | Jun 29 |
| Pumpkin | Apr 12 | May 10–May 10 | 139 | fits: 100 days to maturity, 139 available after May 10. | Jun 4 |
| Cauliflower | Mar 15 | Apr 19–May 3 | 188 | fits: 75 days to maturity, 188 available after Apr 19. | Jul 27 |
| Swiss Chard | Mar 1 | Apr 12–Apr 12 | 195 | two-plantings: Plant Apr 12 and again by Aug 16; both mature before Oct 24. | Aug 16 |
| Arugula | — | Mar 1–May 24 | 251 | two-plantings: Plant Mar 1 and again by Sep 14; both mature before Nov 7. | Sep 14 |
| Brussel Sprouts | Mar 1 | Mar 29–Apr 12 | 223 | fits: 100 days to maturity, 223 available after Mar 29. | Jul 16 |
| Butternut Squash | Apr 12 | May 10–May 17 | 139 | fits: 100 days to maturity, 139 available after May 10. | Jun 4 |
| Eggplant | Mar 8 | May 10–May 17 | 132 | fits: 70 days to maturity, 132 available after May 10. | Jun 27 |
| Okra | Mar 29 | May 3–May 10 | 153 | two-plantings: Plant May 3 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Basil | Mar 22 | May 17–May 17 | 139 | two-plantings: Plant May 17 and again by Jul 21; both mature before Oct 3. | Jul 21 |
| Cilantro | — | Mar 29–Apr 19 | 209 | two-plantings: Plant Mar 29 and again by Aug 21; both mature before Oct 24. | Aug 21 |
| Parsley | Feb 15 | May 3–May 10 | 174 | fits: 70 days to maturity, 174 available after May 3. | Aug 1 |
| Celery | Feb 15 | May 3–May 17 | 174 | fits: 120 days to maturity, 174 available after May 3. | Jun 12 |
| Scallions | Feb 15 | Mar 29–Apr 12 | 223 | two-plantings: Plant Mar 29 and again by Aug 25; both mature before Nov 7. | Aug 25 |
| Turnip | — | Mar 29–Apr 12 | 223 | two-plantings: Plant Mar 29 and again by Sep 4; both mature before Nov 7. | Sep 4 |
| Kohlrabi | — | Mar 15–Mar 29 | 237 | two-plantings: Plant Mar 15 and again by Aug 30; both mature before Nov 7. | Aug 30 |
| Bok Choy | Mar 29 | Apr 19–Apr 26 | 188 | two-plantings: Plant Apr 19 and again by Aug 26; both mature before Oct 24. | Aug 26 |
| Collards | Feb 15 | Mar 29–Apr 12 | 223 | two-plantings: Plant Mar 29 and again by Aug 25; both mature before Nov 7. | Aug 25 |
| Cantaloupe | Apr 12 | May 10–May 17 | 132 | fits: 85 days to maturity, 132 available after May 10. | Jun 12 |
| Chives | Feb 1 | May 3–May 10 | 188 | fits: 90 days to maturity, 188 available after May 3. | — |
| Dill | — | Mar 1–May 24 | 237 | two-plantings: Plant Mar 1 and again by Aug 16; both mature before Oct 24. | Aug 16 |
| Oregano | Feb 15 | May 3–May 10 | 188 | fits: 80 days to maturity, 188 available after May 3. | — |
| Rosemary | Feb 1 | May 3–May 10 | 174 | fits: 80 days to maturity, 174 available after May 3. | — |
| Sage | Mar 1 | May 3–May 10 | 188 | fits: 75 days to maturity, 188 available after May 3. | — |
| Thyme | Feb 15 | May 3–May 10 | 188 | fits: 90 days to maturity, 188 available after May 3. | — |
| Calendula | Mar 15 | Apr 12–Apr 26 | 195 | two-plantings: Plant Apr 12 and again by Aug 21; both mature before Oct 24. | Aug 21 |
| Cosmos | Mar 29 | Apr 26–May 10 | 160 | two-plantings: Plant Apr 26 and again by Jul 21; both mature before Oct 3. | Jul 21 |
| Lavender | Feb 1 | Apr 26–May 10 | 195 | fits: 90 days to maturity, 195 available after Apr 26. | — |
| Marigolds | Mar 15 | Apr 26–May 3 | 160 | two-plantings: Plant Apr 26 and again by Jul 31; both mature before Oct 3. | Jul 31 |
| Melons | Apr 12 | May 10–May 17 | 132 | fits: 85 days to maturity, 132 available after May 10. | Jun 12 |
| Mint | — | Apr 26–May 10 | 195 | fits: 90 days to maturity, 195 available after Apr 26. | — |
| Nasturtiums | Mar 29 | Apr 26–May 3 | 160 | two-plantings: Plant Apr 26 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Pole Beans | — | May 3–May 17 | 153 | fits: 65 days to maturity, 153 available after May 3. | Jul 16 |
| Spaghetti Squash | Apr 12 | May 10–May 17 | 139 | fits: 90 days to maturity, 139 available after May 10. | Jun 14 |
| Sunflowers | — | Apr 26–May 10 | 160 | fits: 70 days to maturity, 160 available after Apr 26. | Jul 11 |
| Tomatillos | Mar 1 | May 3–May 10 | 139 | fits: 75 days to maturity, 139 available after May 3. | Jun 22 |
| Watermelon | Apr 12 | May 3–May 10 | 139 | fits: 80 days to maturity, 139 available after May 3. | Jun 17 |
| Yellow Squash | Apr 12 | May 10–May 17 | 146 | two-plantings: Plant May 10 and again by Jul 26; both mature before Oct 3. | Jul 26 |
| Zinnias | Mar 29 | Apr 26–May 10 | 160 | two-plantings: Plant Apr 26 and again by Jul 21; both mature before Oct 3. | Jul 21 |
Month by month in Rockwood
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 1), Lavender (Feb 1), Onion (Feb 1), Rosemary (Feb 1), Celery (Feb 15), Collards (Feb 15), +5 more. |
| March | Start indoors: Broccoli (Mar 1), Brussel Sprouts (Mar 1), Cabbage (Mar 1), Lettuce (Mar 1), Sage (Mar 1), Swiss Chard (Mar 1), +14 more. Direct sow from: Arugula (Mar 1), Beets (Mar 1), Dill (Mar 1), Peas (Mar 1), Radish (Mar 1), Spinach (Mar 1), +3 more. Transplant from: Broccoli (Mar 29), Brussel Sprouts (Mar 29), Cabbage (Mar 29), Collards (Mar 29), Kale (Mar 29), Lettuce (Mar 29), +2 more. Plant: Strawberry (Mar 22). |
| April | Start indoors: Cucumber (Apr 5), Butternut Squash (Apr 12), Cantaloupe (Apr 12), Melons (Apr 12), Pumpkin (Apr 12), Spaghetti Squash (Apr 12), +3 more. Direct sow from: Carrots (Apr 5), Potatoes (Apr 12), Sunflowers (Apr 26). Transplant from: Calendula (Apr 12), Swiss Chard (Apr 12), Bok Choy (Apr 19), Cauliflower (Apr 19), Cosmos (Apr 26), Lavender (Apr 26), +4 more. Last frost around April 26. |
| May | Direct sow from: Beans (May 3), Pole Beans (May 3). Transplant from: Celery (May 3), Chives (May 3), Corn (May 3), Okra (May 3), Oregano (May 3), Parsley (May 3), +17 more. |
| June | Last sowing dates: Butternut Squash (Jun 4), Pumpkin (Jun 4), Cantaloupe (Jun 12), Celery (Jun 12), Melons (Jun 12), Spaghetti Squash (Jun 14), +6 more. |
| July | Last sowing dates: Sunflowers (Jul 11), Brussel Sprouts (Jul 16), Pole Beans (Jul 16), Basil (Jul 21), Cosmos (Jul 21), Cucumber (Jul 21), +9 more. |
| August | Last sowing dates: Parsley (Aug 1), Peas (Aug 6), Cabbage (Aug 15), Carrots (Aug 15), Beets (Aug 16), Dill (Aug 16), +9 more. |
| September | Last sowing dates: Turnip (Sep 4), Arugula (Sep 14), Spinach (Sep 14), Radish (Sep 15). |
| October | Direct sow from: Garlic (Oct 17). First frost around October 17. |
| November | Last sowing dates: Garlic (Nov 7). |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Rockwood, MI (ZIP 48173)?
The median last spring frost date for Rockwood, MI (ZIP code 48173) is around April 26. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before April 11; one in ten it runs past May 10.
What is the first fall frost date in Rockwood, MI?
The median first fall frost date for Rockwood, MI is around October 17. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around October 4 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Rockwood, MI?
The frost-free growing season in Rockwood is about 174 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Rockwood (174 frost-free days, a moderate season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Rockwood, MI?
Rockwood, MI is in USDA hardiness zone 6b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Rockwood, MI?
Start tomatoes indoors Mar 22 and plant out May 10 in Rockwood. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Rockwood?
Two: plant Mar 29 and again by Aug 26; both mature before Oct 24.
When do I plant garlic in Rockwood?
Oct 17 to Nov 7; it overwinters and is ready the following summer.
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