When to plant Ageratum in Howard County, MO
Plant Ageratum in Howard County after April 13; the prime window is April 13–May 4.
When to Plant Ageratum in Howard County, MO
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.
Howard County, Missouri is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.
At an elevation of 945 feet, Howard County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Ageratum during the growing season.
Howard County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.9
Drainage
Well Drained
Monthly Watering Guide for Ageratum
Ageratum needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Ageratum Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Howard County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Howard County, MO
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Direct Sow | April 13 | Apr 13 – May 4 |
| Bloom | June 8 | Jun 8 – Sep 21 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Direct Sow |
| June | Bloom |
| 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 6b
📆 Growing Season
194 days in Howard County
Growing Tips for Howard 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 Howard County, MO?
Howard County is in Zone 6b with an average last frost of April 13. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Howard County, MO?
Howard County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 24.
When should I plant Ageratum in Howard County, MO?
In Howard County, MO, plant Ageratum after the last frost (around April 13) and before the first frost (around October 24). Best results when soil holds above 50°F.
What growing zone is Howard County, MO for Ageratum?
Howard County sits in USDA Zone 6b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Ageratum grow in Howard County's climate?
Yes — Ageratum grows well in Howard County's temperate climate. Howard County averages a 194-day frost-free season, with last frost around April 13 and first frost around October 24.
Your Howard County Garden Planner — Free
A 22-page printable planner built for Howard County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.