When to Plant Ageratum in Grande Prairie, AB
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.
Grande Prairie, Alberta is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is October 9, giving you a growing season of approximately 140 days.
At an elevation of 2,194 feet, Grande Prairie receives approximately 19 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 75°F, so choose short-season varieties of Ageratum to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Ageratum successfully. Mulch heavily to conserve soil moisture.
Grande Prairie Soil Profile
Soil Type
Dark Brown Chernozem
Soil pH
6.0-7.0
Drainage
Well Drained
Ageratum Planting Timeline — Grande Prairie, AB
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 27 | Mar 27 – Apr 10 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 29 | May 29 – Jun 19 |
| Bloom | July 24 | Jul 24 – Oct 2 |
· 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 | Bloom |
| 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 4a
📆 Growing Season
140 days in Grande Prairie
Growing Tips for Grande Prairie
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 Grande Prairie, AB?
Grande Prairie is in Zone 4a with an average last frost of May 22. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grande Prairie, AB?
Grande Prairie, Alberta is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is October 9.
Your Grande Prairie Garden Planner — Free
A 22-page printable planner built for Grande Prairie (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.