Cosmos are native to Mexico. In the U.S. these old-fashion annuals bloom throughout the summer months and attract birds, bees, and butterflies to your garden. They produce colorful 2- to 4-inch wide daisy-like flowers that sit atop 3-5 feet tall slender stems. Cosmos make excellent cut flowers and dwarf forms are ideal in containers.

Annual cosmos grows in average well-drained soils and in partial to full sun. To avoid staking cosmos, tall varieties are best in full sun and in poor, fairly dry soils. Over-watering and over-fertilization can lead to plants with fewer flowers. Shelter cosmos from strong winds. Plant taller plants close enough for plants to support one another. Deadhead spent flowers to prolong bloom, but just enough flower heads for self-seeding.

Cosmos are low-maintenance annuals. Summer medium green leaves are deeply cut into threadlike segments. Floral colors range from red, pink, orange, yellow, white, and bi-colors. Cultivars feature single, semi-double or double flowers that range in height from dwarf (1.5 feet) to tall (6 feet). Floral heads may be flat or cup–shaped.

Two species are commonly listed in plant and seed catalogs. Cosmos bipinnatus come in pink, red, white, lavender, and bicolors. C. sulfureus come in yellow, orange and scarlet orange, and bicolors. Some varieties produce semi-double flowers. Deadheading dead or faded flowers encourages more flowering and better branching by pinching out the central shoots or stem tips. Some varieties grow very tall and may require staking. Mostly trouble-free, powdery mildew, stem cankers, aphids can be occasional problems.

Gardeners may opt to direct seed cosmos. For earlier flowering start the seeds indoors 6-8 weeks before the late frost forecast in your region. Cosmos self-seed readily. Either purchase seeds at garden shops or collect dried seeds late in the fall to sow next year. Know that seeds from hybrid varieties may not “come true” to the parent plant.

Varieties: C. bipinnata ‘Radiance’ (wine red), ‘Candy Stripe’, ‘Daydream’, ‘Sensation’, ‘Sunny Red’.

C. sulphureus ‘Bright Lights’, ‘Cosmic Orange’, ‘Lemon Twist’, ‘Klondike’ (orange).