Cosmos ’Rosetta’
Cosmos bipinnatus
Description
This variety is a must-have for arranging and wedding work, and flowers are stunning arranged en masse. Blooms have a layer of half-double petals that resemble fluffy petticoats. ‘Rosetta’ is a mix of soft pink, blush, and rose with each petal appearing as if it was hand painted. Cosmos are one of the easiest cut flowers you can grow and are perfect for beginners.
Details
Plant type: annual
Height: 36 to 42 in
Site: full sun
Days to maturity: 75 to 90 days
Plant spacing: 12 in
Pinch: when 8 to 12 in tall
Height: 36 to 42 in
Site: full sun
Days to maturity: 75 to 90 days
Plant spacing: 12 in
Pinch: when 8 to 12 in tall
Seed Sowing & Growing Notes
Start seed indoors in trays 4 to 6 weeks before last frost; transplant out after all danger of frost has passed. Cosmos can also be direct-seeded once the weather has warmed.
Harvesting/Vase Life
Harvest when buds are just cracking, but haven’t fully opened. For double varieties, let open halfway before picking. Expect a vase life of 5 to 6 days.
Details
Description
This variety is a must-have for arranging and wedding work, and flowers are stunning arranged en masse. Blooms have a layer of half-double petals that resemble fluffy petticoats. ‘Rosetta’ is a mix of soft pink, blush, and rose with each petal appearing as if it was hand painted. Cosmos are one of the easiest cut flowers you can grow and are perfect for beginners.
Details
Plant type: annual
Height: 36 to 42 in
Site: full sun
Days to maturity: 75 to 90 days
Plant spacing: 12 in
Pinch: when 8 to 12 in tall
Height: 36 to 42 in
Site: full sun
Days to maturity: 75 to 90 days
Plant spacing: 12 in
Pinch: when 8 to 12 in tall
Seed Sowing & Growing Notes
Start seed indoors in trays 4 to 6 weeks before last frost; transplant out after all danger of frost has passed. Cosmos can also be direct-seeded once the weather has warmed.
Harvesting/Vase Life
Harvest when buds are just cracking, but haven’t fully opened. For double varieties, let open halfway before picking. Expect a vase life of 5 to 6 days.
Sources
How to Grow
Sources
How to Grow
Seed-Saving Mini Course
Learn how to save seed from zinnia, dahlia, and celosia
In our free, three-part video series, you’ll learn everything you need to know to save seeds on a home scale, including how plants are pollinated and isolation techniques to ensure varieties come back true, how to tell when plants are ready to pick and how to harvest the seeds, and how to properly dry, clean, and store seeds long term.
