When to plant Coreopsis in Roseau County, MN
Roseau County sits in cold Zone 3b. Plant Coreopsis May 28–June 18 for the single annual harvest; the September 22 first frost closes the window.
When to Plant Coreopsis in Roseau County, MN
Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.
Roseau County, Minnesota is in USDA Zone 3b. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.
At an elevation of 655 feet, Roseau County receives approximately 32 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Coreopsis to ensure they mature before fall.
Roseau County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Coreopsis Planting Timeline — Roseau County, MN
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 12 | Mar 12 – Mar 26 |
| Transplant Outdoors | June 4 | Jun 4 – Jun 18 |
| Direct Sow | May 28 | May 28 – Jun 18 |
| Bloom | August 27 | Aug 27 – Oct 29 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 3b
📆 Growing Season
124 days in Roseau County
Growing Tips for Roseau County
Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Coreopsis in Other Locations
Frequently Asked Questions
When should I plant Coreopsis in Roseau County, MN?
Roseau County is in Zone 3b with an average last frost of May 21. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Roseau County, MN?
Roseau County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 21 and first fall frost is September 22.
When should I plant Coreopsis in Roseau County, MN?
In Roseau County, MN, plant Coreopsis after the last frost (around May 21) and before the first frost (around September 22). Best results when soil holds above 50°F.
What growing zone is Roseau County, MN for Coreopsis?
Roseau County sits in USDA Zone 3b. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Roseau County's climate?
Yes — Coreopsis grows well in Roseau County's temperate climate. Roseau County averages a 124-day frost-free season, with last frost around May 21 and first frost around September 22.
Your Roseau County Garden Planner — Free
A 22-page printable planner built for Roseau County (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.