Cosmos (Cosmos bipinnatus)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers

Annual

Cosmos
Cosmos bipinnatus

 
Features
An easy care annual that offers colorful flowers all summer, lacy foliage and attracts butterflies and birds. Useful as a cutting garden plant, or in a wild meadow garden. Self seeds freely. 
 
Culture
Full sun with soils that are well-drained and low fertility. Keep flowers deadheaded for continual bloom. Support may be needed for taller cultivars or plant close so they support each other. Very successful when directly sown into the garden. 
 
Cultivars
  • 'Versailles' series
  • 'Sonata' series
  • 'Daydream'
  • 'Seashell'
  • 'Loveliness' (double)
 
 
Mature Height
12-24 Inches
 
Size
Medium
Tall
 
 
Annual Hardiness Type
Tender Annual
 
 
Bloom Color
Pink
Red
White
Yellow
 
 
Bloom Season
June - October
 
Soil Conditions
Moist, Well-Drained
 
 
Exposure/Light Requirements
Full Sun
 
 
Pests and Problems
 
Additional Notes
Overfertilization and overwatering can lead to plants that have fewer flowers.

 

 
Related Resources
Home, Yard & Garden Pest Guide
Illinois Commercial Landscape and Turfgrass Pest Management Handbook
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic