When to plant Cosmos in Sherburne County, MN
Plant Cosmos in Sherburne County from May 8 to May 29 in spring. Sherburne County sits in USDA Zone 4b, with last frost around May 1 and first frost on October 6.
When to Plant Cosmos in Sherburne County, MN
Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.
Sherburne County, Minnesota is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 6, giving you a growing season of approximately 158 days.
At an elevation of 568 feet, Sherburne County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Cosmos to ensure they mature before fall.
Sherburne County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Cosmos Planting Timeline — Sherburne County, MN
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Direct Sow | May 8 | May 8 – May 29 |
| Bloom | July 17 | Jul 17 – Oct 9 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
158 days in Sherburne County
Growing Tips for Sherburne County
Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Sherburne County, MN?
Sherburne County is in Zone 4b with an average last frost of May 1. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sherburne County, MN?
Sherburne County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 6.
When should I plant Cosmos in Sherburne County, MN?
In Sherburne County, MN, plant Cosmos after the last frost (around May 1) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Sherburne County, MN for Cosmos?
Sherburne County sits in USDA Zone 4b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Sherburne County's climate?
Yes — Cosmos grows well in Sherburne County's temperate climate. Sherburne County averages a 158-day frost-free season, with last frost around May 1 and first frost around October 6.
Your Sherburne County Garden Planner — Free
A 22-page printable planner built for Sherburne County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.