Ageratum ageratum

(a-jur-aa' tum)

Common name: Ageratum, Mexican Ageratum, Flossflower

Family: Asteraceae, Aster

Height x width: 4-24" x 8-24"

Growth rate: moderate

Foliage: opposite leaves, usually oval with rounded teeth

Flowers: blue, white, pink 1/4" flower heads (tassel-like) in cymose clusters without ray flowers

Hardiness: annual

Soil: well-drained, moist, fertile

Light: sun preferred or part shade in zones 8-9

Pests and problems: root rot, powdery mildew, spider mites

Landscape habit, uses: edging or border front for low cultivars with mounded habit, mid to back borders for taller

Other interest: native of Mexico; genus from Greek words a- meaning not and geros meaning old age, refering to the flowers not appearing old for a long period

Other culture: remove flower heads to ensure continued bloom, prefer warm weather

Propagation: seed indoors to plant out (214,000 seeds/oz.) which germinate in 5-10 days, also latter in season by cuttings


houstonianum (hu-sto-nee-aa' num)--usually seen species, named for botanist Dr. W. Houston who brought plants back from Mexico and the West Indies

Cultivars: (of houstonianum), those marked * are most common 

Cultivars height, in flowers other
'Adriatic' 8 mid-blue early, heat tolerant, common
'Bavaria' 9-12 blue, white bicolor  
'Blue Blazer' 5-6 deep-blue common
'Blue Danube' ('Blue Puffs') 7 bright blue uniform, common
'Blue Hawaii' 8 mid-blue small leaves,compact,common
'Blue Heaven' 6 mid-blue heat tolerant
*'Blue Horizon' 24-30 mid-blue vigorous, branched, good cut
'Blue Jay' 4 powder blue common
'Blue Lagoon' 8 medium blue uniform, compact, heat-tolerant
'Blue Mink' 12 powder blue early, tetraploid, common
'Blue Ribbon' 4-5 mid-blue compact, low
'Blue Puffs':'Blue Danube'      
'Capri' 8 deep blue compact, non-hybrid
'Fine Wine' 6-8 burgundy red compact
*Hawaii Hybrids 8 blue, purple, white small leaves, compact 
'Madison' 8 blue  
'Midget Blue' 5 bluish-mauve  
'Neptune Blue' 8 mid-blue
'North Sea' 8 lavender-blue reddish buds, common
'Pacific' 8 purple-violet early, uniform, common
'Pinky Improved' 6-8 dusky pink unusual color
'Royal Delft' 6 deep violet-blue compact
'Southern Cross' 8-12 blue, white bicolor good for cutting
'Summer Snow' 6 pure white common
Swing Hybrids 6-8 blue, rose, pink  

©Authored by Dr. Leonard Perry, Professor, University of Vermont as part of PSS123 course.

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