When to plant Marigolds in St. Clair County, MI
The best window to plant Marigolds in St. Clair County, is May 4–May 25, when soil warms to 50°F. Last frost typically hits April 27; first frost October 27.
When to Plant Marigolds in St. Clair County, MI
Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.
St. Clair County, Michigan is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 27, giving you a growing season of approximately 183 days.
At an elevation of 1,065 feet, St. Clair County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Marigolds during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Marigolds Planting Timeline — St. Clair County, MI
Marigolds Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 16 | Mar 16 – Mar 30 |
| Transplant Outdoors | May 4 | May 4 – May 18 |
| Direct Sow | May 4 | May 4 – May 25 |
| Bloom | June 29 | Jun 29 – Sep 28 |
Plant 0.3" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
183 days in St. Clair County
Growing Tips for St. Clair County
Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.
Marigolds in Other Locations
Frequently Asked Questions
When should I plant Marigolds in St. Clair County, MI?
St. Clair County is in Zone 6a with an average last frost of April 27. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, MI?
St. Clair County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 27.
When should I plant Marigolds in St. Clair County, MI?
In St. Clair County, MI, plant Marigolds after the last frost (around April 27) and before the first frost (around October 27). Best results when soil holds above 50°F.
What growing zone is St. Clair County, MI for Marigolds?
St. Clair County sits in USDA Zone 6a. Marigolds grows reliably in zones 2a through 11b, so it's a good fit here.
Can Marigolds grow in St. Clair County's climate?
Yes — Marigolds grows well in St. Clair County's temperate climate. St. Clair County averages a 183-day frost-free season, with last frost around April 27 and first frost around October 27.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.