When to plant Ageratum in Clearwater County, MN
Plant Ageratum in Clearwater County, between May 29 and June 19 — the only viable window. Zone 3b's short season (136 frost-free days) rules out a fall crop.
When to Plant Ageratum in Clearwater County, MN
Ageratum (Ageratum houstonianum), the floss flower, produces clusters of fluffy, powder-puff blooms in the rare sky-blue and lavender tones difficult to find among warm-season annuals. Compact mounding habit makes it ideal as a front-of-border edging plant. Blooms from early summer through fall with minimal deadheading; heat and humidity tolerant once established.
Clearwater County, Minnesota is in USDA Zone 3b. The average last spring frost is May 15 and the first fall frost is September 28, giving you a growing season of approximately 136 days.
At an elevation of 1,074 feet, Clearwater County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Ageratum to ensure they mature before fall.
Clearwater County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Ageratum Planting Timeline — Clearwater County, MN
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 29 | May 29 – Jun 19 |
| Bloom | July 24 | Jul 24 – Sep 25 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 3b
📆 Growing Season
136 days in Clearwater County
Growing Tips for Clearwater County
Start seeds indoors 6–8 weeks before last frost — do not cover seed; it needs light to germinate. Can be direct-sown after last frost once soil warms to 60°F. Transplant or thin to proper spacing after frost danger passes. Deadheading isn't strictly required but tidying spent clusters improves appearance. Provide consistent moisture; drought causes premature setting. Avoid deep shade — blooms best in full sun to light afternoon shade.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Ageratum in Other Locations
Frequently Asked Questions
When should I plant Ageratum in Clearwater County, MN?
Clearwater County is in Zone 3b with an average last frost of May 15. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clearwater County, MN?
Clearwater County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 15 and first fall frost is September 28.
When should I plant Ageratum in Clearwater County, MN?
In Clearwater County, MN, plant Ageratum after the last frost (around May 15) and before the first frost (around September 28). Best results when soil holds above 50°F.
What growing zone is Clearwater County, MN for Ageratum?
Clearwater County sits in USDA Zone 3b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Clearwater County's climate?
Yes — Ageratum grows well in Clearwater County's temperate climate. Clearwater County averages a 136-day frost-free season, with last frost around May 15 and first frost around September 28.
Your Clearwater County Garden Planner — Free
A 22-page printable planner built for Clearwater 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.