Blue Horizon flossflower
Ageratum houstonianum 'Blue Horizon'
RHS AGM 1995; MBG Plant of Merit 2008
USDA zones2 to 11
SunHandles full sun to partial sun
WaterHandles moderate to moist soil
Size1 to 2.5 feet tall6 to 18 inches wide
- Growth rate
- Moderate
- Bloom season
- Spring, summer, autumn
- Bloom color
- Lavender to purplish-blue
- Soil types
- Sand, loam, clay, chalk
- Soil pH
- Acid, alkaline, neutral
Garden uses
Attracts
Notes
'Blue Horizon' flossflower (Ageratum houstonianum 'Blue Horizon') is an annual for borders, containers, cut flowers, and pollinator gardens. It is not cold-hardy and will not survive freezing temperatures. This plant likes full or part sun and average to moist soil of most types. It bears lavender to purplish-blue blooms and draws butterflies and bees. It reaches 12 to 30 inches tall and tolerates drought. Deer and rabbits tend to browse other plants first.
Pairs well with Supertunia Bordeaux petunia, Sensation Mix cosmos, and Red fescue.