Sun-loving cosmos produce colorful ray flowers throughout the warm season on tall, airy stems. From summer through frost, ray flowers in vivid shades of yellow, bright pink, lavender, red, chocolate, and many more grow with carefree ease. The summer annual is native to the Americas and lends a wildflower look to the display. The wanding bloomers are easy to grow, attract bees, butterflies, and hummingbirds, and are drought-tolerant.
Cosmos are unfussy and thrive with a bit of neglect. They prefer hot, dry conditions with variable soils. Too much water, fertilizer, or organic richness hinders their vigor. Plant them in a mass for waves of color and to attract pollinators. Deadhead spent blooms or cut them regularly to enjoy as fresh florals. They reward us with more blooms in wild cosmos colors.
Growing Cosmos From Seed
Cosmos grow quickly from seed, are easy to sow, and come in gorgeous hues. They have a fast germination and growth rate, and some varieties mature in as little as 50 days. Direct sow them outside one to two weeks after spring’s final frost, with ideal soil temperatures above 60°F (16°C). You can also start them indoors four to six weeks before transplanting in spring. Soil blocking is a handy method for cosmos that saves resources.
Cosmos reseed in the landscape for future flowering. When flowers fade and go to seed, cut stems back to 12 to 18 inches tall for a quick rebloom. Let the cut stems fall in place so new seeds germinate for the next generation of blooms. Songbirds also enjoy them as forage.
‘Apricotta’
‘Apricotta’ is an award-winning variety with blooms in multiple peachy pink shades. Petals have lavender-pink interiors with gradation to dusky apricot. The centers are bright yellow buttons, and the effect is a swirl of color. Cupped petals give a lit-from-within glow at four inches across.Â
‘Apricotta’ won the revered Fleuroselect Novelty award for its stunning color. Tall, sturdy stems make them ideal for fresh bouquets. This variety produces bundles of vibrant blooms, pretty in a sweeping mass or complement to other warm season blooms. ’Apricotta Lemonade’ cosmos bring the same peach tones to deliciously creamy yellow outer petals for a soft arrangement.
Chocolate
These cosmos look and smell delicious. A tender, herbaceous perennial, Cosmo atrosanguineus is striking in both flower and fragrance. Velvety, mahogany-red blooms bear a chocolate scent to match.
Chocolate cosmos are hardy in zones 7-10, with extra mulch in winter on the fringes of zone 7. In colder climates, grow them as annuals or lift the tubers in late fall when foliage fades. Dig the tubers and store them indoors in a damp medium (sand, wood shavings, vermiculite) in an open crate or box until temperatures warm in spring. Chocolate cosmos divide easily through their tubers.Â
‘Black Magic’ is an innovation on the heirloom species native to Mexico. The cultivar has larger blooms (but still small at two inches) with waxy petals around a prominent center. Use them in floral arrangements, in the cottage garden, and in containers for up-close chocolatey delight.
‘Xanthos’
‘Xanthos’ brings unique cosmo color combined with early blooms. Petals are lemon and lime yellow with white edges and halos around the centers. Mostly single blooms, some have a small ring of double petals on the interior.
Soft and bright, their coloration is a sweet combination among the species. ‘Xanthos’ is another Fleuroselect Novelty Award winner and Gold Medal recipient for its color and form. ‘Xanthos’ shakes up the display with shorter, well-branched stems perfect for the border or container arrangements. Â
‘Rubenza’
To contrast pastels, whites, and bright shades is ‘Rubenza’ in deep scarlet. Wine petals age to dusky rose for a multi-tonal effect on each plant. The dramatic three-inch flowers with sunny yellow discs are pollinator magnets. Their edges have slight ruffles and scallops, and the foliage is feathery, bright green for detailed interest.
Burgundy tones in the garden bring depth to the composition. Deep red shades stand out among leafy greens to punctuate the display. While an unexpected cosmos color, the dark red shades are striking neutrals and complement almost any other blooming or foliage specimen. Use these Fleuroselect winners in the vase for a moody contrast. ‘Rubenza’ is also a Royal Horticultural Society Award of Garden Merit recipient.
‘Candystripe’
‘Candystripe’ brings a dynamic duo of a crisp white ground color with painterly cerise margins. The brushed red-pink edges give a peppermint swirl to the masses of white rays. Cheery yellow centers make this a friendly bloom to brighten the composition.
While magenta margins define each petal, the markings vary with an artful appeal. This cosmos color shines amongst deep, leafy greens.
‘Sea Shells Blend’
These unique beauties have fluted, rolled petals in rose, white, pink, and crimson. The distinctive cosmos add variety in texture and color. On tall stems, the large blooms (three to four inches across) wave in the breeze.
Most blooms are a single color in one of the blended shades, but some are bicolor with darker interiors and tubes. The slight ruffles of ‘Sea Shells Blend’ add detail to fresh florals. The thicker, fuller petals stand out in the flowerbed and vase.
‘Diablo’
Throw some fiery cosmos color in the garden with the semi-double blooms of ‘Diablo’ in radiant orange and gold. The full flowers rise on tall stems and are a beacon for bees, butterflies, and hummingbirds.Â
This classic All-America Selections winner is a favorite for its bold petals in color, form, and floriferousness. Each plant produces loads of small, full flowers at an inch and a half across. Blooms have tints of scarlet and yellow, often bicolor, for excitement in the display.
Employ ‘Diablo’ at the back of the border or with lower-growing specimens as supports for the tall stems. Protect it from areas with high winds because the variety grows tall, though sulfur cosmos show good branching.
‘Sensation Blend’
‘Sensation’ is an All-America Selections winner from 1936. The old-fashioned beauty brings scalloped petals in bicolor shades from soft pink to bubblegum to magenta. The broad, pleated petals show darker interiors around yellow centers. The tissuey blooms pop against fresh green, narrow-bladed foliage.
‘Sensation Blend’ combines shades of pink, crimson, white, and rose. Three to four-inch faces top very tall stems. With the blended tones, a complementary mass of dynamic cosmos color is at the ready. The Award of Garden Merit recipients pack the blooms per square foot.
‘Xsenia’
For technicolor hues, look to the ‘Xsenia’ in glowing magenta, carmine, and rose. Earthy orange notes underlie the rosy pink and reds on petal interiors with brighter edges. The vivid shades age to antique rose.Â
Like ‘Xanthos,’ ‘Xsenia’ is early to flower. The smaller blooms on sturdy, well-branched, upright stems bring reliable, tidy sweeps of color. The two-and-a-half-inch multicolored flowers crowd stems for a robust display. While dynamic in varying shades, the stunning pick complements other flowers and foliage without glaring clashes in the border or fresh floral design.
The Fleuroselect Novelty Award winner works well for shorter stem displays. Pinch seedlings at 8 to 10 inches tall to encourage bushy growth.
‘Cupcakes White’
The ‘Cupcakes’ series brings novel floral forms in sweet shades. In pure white, ‘Cupcakes White’ graces the composition with structural flowers and fused petals that resemble a crimped paper cup. The crisp origami blooms with flutes and scalloped margins offer dynamic interest. Punctuated with yellow centers, they shine in the sun.
‘Cupcakes White’ has lightweight, airy, upright blossoms on sturdy stems. Some of the blooms give a bonus of a wreath of extra petals at the center. For other intriguing pure white selections, look for ‘Double Click Snow Puff’ with fluffy double petals and ‘Purity’ with prominent fuzzy yellow centers.Â
‘Double Click Blend’
‘Double Click’ brings a sea of fluffy double blooms with this blend of cranberry, rose, white, and pink. Each selection is showstopping on its own, but in blended shades, the complementary mix brings depth and layers of cosmos colors. Another Fleuroselect winner, it’s exceptional in fresh arrangements.
‘Double Click Blend’ varieties are mostly double-petaled, some semi-double, for full, feathery, and tufted forms. Some are bicolor with flares and flutes. Dark cranberry contrasts the pale shades beautifully. The intermediate-length stems hold the robust three to four-inch flowers aloft.
‘Bright Lights Blend’
Give the cottage garden a glow-up with ‘Bright Lights Blend’ The illuminated blossoms in orange, scarlet, and gold are abundant among the finely-divided foliage.Â
‘Bright Lights’ is like a neon sign for pollinators, drawn to the profusion of two-and-a-half-inch blooms for their plentiful nectar and pollen. The vibrant rays overlap for a burst of sunshine in the border.
‘Velouette’
‘Velouette’ is a voluminous display of variations in scarlet and white. From solid, deep red faces to petals striped in white and burgundy, the candy-striped variety is dynamic in an overall blend of reds, whites, and pinks. The delicate brushed streaks give a swept, silky look to the petals for added movement in the display.
‘Velouette’ has Award of Garden Merit status for its unique cosmos color and landscape performance. While not garish, it is a highlight in bunched bouquets.
