Bright green fernlike foliage is the perfect complement to the daisylike flowers of cosmos, which come in shades of white, pink, yellow, or orange. This cottage-garden favorite is a magnet for pollinators and easily grown from seed sown directly in the garden. Plant petite varieties, such as ‘Little Ladybirds’, in containers for a pretty splash of color on the patio. Because cosmos is so easy to grow, it makes a fun choice for a children’s garden.
Depending on the variety, cosmos features single saucer-shape flowers with yellow centers and white, pink, or red rays. This annual's green leaves are deeply cut into feathery threadlike segments. Cosmos cultivars sport a larger number of colors than regular cosmos, including bicolor, expressed in single, semi-double, or double flowers. Look for sizes ranging from dwarf to tall.
Cutting Garden Essential
Pair cosmos with three or four other easy-to-grow annuals and enjoy weeks of freshly cut flowers right from your own garden. Anchor the cutting garden with multiple varieties of cosmos. Try 'Cupcake White' or 'Psyche White' along with the 'Sonata' mix in white, pink, rose, and cherry. You may also want to include other annuals like zinnias, sunflowers, larkspur, bells of Ireland, and bachelor's buttons.
For a low-maintenance cutting garden that is low-cost, too, grow cutting flowers from seeds planted in rows. The row-style planting makes it easy to manage weeds. A $15 investment in seeds will yield armloads of flowers in multiple varieties.
Cosmos Care Must-Knows
This tough warm-weather annual does best in well-drained soil in full sun. Directly sow cosmos seeds in the garden just before the last frost date in spring. Sow seeds 2-3 inches apart and ¼-inch deep, then lightly cover with fine soil and water well. Seedlings will emerge in 5-10 days. Keep the seed bed well weeded and watered. Cosmos will begin blooming about two months after planting. If you prefer to start seeds indoors, do so 6-8 weeks before your last frost date in spring.
Related: Deadheading for Extended Bloom
Plants that come from tall cosmos varieties should be spaced close to each other for support. They still may need staking. Use tall bamboo stakes and garden twine to support plants quickly and easily. Deadhead spent flowers to encourage plants to unfurl new flowers. Leave some flowerheads for self-seeding, if desired. When planted in the garden, cosmos does not need fertilizer. Plants growing in containers flower best when fertilized every two weeks or so with an all-purpose garden fertilizer.