Rubinato Cosmos is a compact, jewel-toned beauty that transforms gardens from summer through fall with deep crimson-burgundy blooms. This cultivar of Cosmos bipinnatus reaches just 18 to 24 inches tall, making it perfect for borders, containers, and small spaces where larger cosmos varieties won't fit. From seed to first flower takes just 56 to 84 days, and once established, this drought-tolerant annual thrives on neglect, asking only for full sun and well-drained soil. Hardy from zones 2 to 11, Rubinato blooms reliably from June through November, attracting pollinators throughout the season with its nectar-rich flowers.
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Full Sun
Low
2-11
24in H x 18in W
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Moderate
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The dark crimson petals of Rubinato Cosmos deliver drama in a surprisingly manageable package. At under two feet tall, this cultivar produces flowers with the same sophisticated color depth as taller varieties, but in a form that doesn't require staking or coddling. Once your cosmos are established and flowering, they ask almost nothing of you; skip the watering cans during normal rainfall and let them do their work attracting bees and butterflies to your garden.
Rubinato Cosmos shines in cut flower arrangements, where its deep burgundy petals add richness and depth to summer and fall bouquets. The compact growth habit and prolific flowering make it excellent for filling in garden borders, softening hardscape edges, and creating waves of color in cottage-style plantings. Container growers appreciate it for its neat size and long blooming season.
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Start seeds indoors in pots 4 to 5 weeks before your last spring frost, keeping soil temperatures around 60 to 75 degrees Fahrenheit. Seeds sprout in 3 to 10 days. Transplant seedlings outdoors after the last frost date when soil has warmed.
Harden off seedlings by gradually exposing them to outdoor conditions over 7 to 10 days before planting. Transplant after your last spring frost when soil temperatures have warmed. Space plants 18 inches apart.
Direct sow seeds in spring after the last frost date. Scatter seeds on prepared soil and press lightly into place; they need light to germinate.
Cut flowers in early morning when blooms are fully open and petals are turgid with water. Cosmos flowers last well in the vase, typically 7 to 10 days. For seed saving, allow a few blooms to fade on the plant; collect dried seed heads in late fall after they've turned brown and papery.
Deadheading spent flowers encourages more blooms throughout the season and extends flowering into late fall. Pinching back young plants when they reach 6 inches tall promotes bushier, more compact growth and fuller flower production.
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