When to plant Cosmos in Pine County, MN
Pine County's short 142-day growing season means one Cosmos planting between May 17 and June 7. No fall crop in Zone 4a.
When to Plant Cosmos in Pine 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.
Pine County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is September 29, giving you a growing season of approximately 142 days.
At an elevation of 538 feet, Pine County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Cosmos to ensure they mature before fall.
Pine County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Monthly Watering Guide for Cosmos
Cosmos needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Cosmos Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Aug | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | — | 2.3" | 0" | ❄️ Dormant |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Pine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos Planting Timeline — Pine County, MN
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 12 | Apr 12 – Apr 26 |
| Transplant Outdoors | May 17 | May 17 – May 31 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Bloom | July 26 | Jul 26 – Oct 11 |
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 | Direct Sow |
| 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 4a
📆 Growing Season
142 days in Pine County
Growing Tips for Pine 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 Pine County, MN?
Pine County is in Zone 4a with an average last frost of May 10. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pine County, MN?
Pine County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is September 29.
When should I plant Cosmos in Pine County, MN?
In Pine County, MN, plant Cosmos after the last frost (around May 10) and before the first frost (around September 29). Best results when soil holds above 50°F.
What growing zone is Pine County, MN for Cosmos?
Pine County sits in USDA Zone 4a. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Pine County's climate?
Yes — Cosmos grows well in Pine County's temperate climate. Pine County averages a 142-day frost-free season, with last frost around May 10 and first frost around September 29.
Your Pine County Garden Planner — Free
A 22-page printable planner built for Pine County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.