Grown as annuals for their attractive flowers and thin foliage, Cosmos have daisy-like flowers. The flowers range from light to dark pink, lavender to deep purple, yellow to orange or red. These relatively fast-growing plants produce a deep taproot, and some varieties can reach 1.8 meters (6 feet) in overall height. Numerous cultivars/varieties/subspecies exist, most staying under a foot tall.
Cosmos bipinnatus (Cosmos, Mexican Aster)
Hardiness Zones: 8-11
Height: 0.3-1.3 meters (1-4 feet) (some cultivars grow up to 1.8 meters (6 feet)) tall, typically under 30 centimeters (12 inches)
Diameter: 60-90 centimeters (24-36 inches) across at absolute largest
Growth Rate: moderate to fast
Root System: taproot root system
Subspecies: ‘Cosmic’ series (dwarves with yellow/orange flowers), ‘Sonata’ series (dwarves,
larger pink/white/red flowers), ‘Candy Stripe Mix’ (white with red stripes), ‘Daydream’
(light and dark pink flowers), ‘Gazebo Mix’ (larger with white, pink, and red flowers),
‘Seashells Mix’ (trumpet-like white/pink/red flowers), ‘Sensation’ series (large with large
white/pink/red flowers), ‘Versailles’ series (large, vibrant blooms), ‘Picotee’ (white
Tolerates: strong winds
Problems (major): none major
Problems (minor): Strong winds can easily bend plants.
Soil requirements: optimum growth in non-fertile, moderate moisture, well-drained soils
with neutral to alkaline pH; sandy, loamy, or clay soils
Air requirements: not sufficiently researched
Watering requirement: moderate
Sun requirement: full sun
Leaf shape: lacy, airy
Leaf size: up to 20 centimeters (8 inches) at most
Flower structure: daisy-like, up to 10 centimeters (4 inches) in diameter, yellow centers,
red/pink/violet/white rays, sometimes bicolor or double-flowers
Flowering frequency: early summer until frost
Self-seeds quickly, these have particularly lacy foliage with their daisy-like flowers.
These are sometimes grown as border plants or specimen plants. The flowers are pink to
lavender with many shades in between.
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