Sonata Carmine

Cosmos

60d to harvest

Velvety petals unfurl in a rich carmine blaze, each bloom catching the light like a small, poised firework above finely laced foliage. Sonata Carmine produces abundant, daisy-like flowers with a crisp, satiny texture and a graceful, upright stance—ideal for long-lasting bouquets and vivid color runs in the garden. Grow it for a steady parade of blooms that make every arrangement feel freshly composed from the first day to the last.

Crop Dates

Milestone	Date
Start Indoors	Direct Sow
Last Frost	May 15th
Transplant / Sow Outdoors	May 15th
Harvest Begins	Jul 14th
Harvest Ends	Sep 24th

Crop Details

Trait	Value
Days to Maturity	60
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Surface
Germination Temp (°F)	75
Min Soil Temp (°F)	60
Min Night Temp (°F)	50
Harden Off (days)	Not Required

Frequently Asked Questions

Cosmos bipinnatus ‘Sonata Carmine’—what pest or disease is most common, and how do I control it?

A frequent problem is powdery mildew, which shows up as a white, dusty coating on cosmos leaves in warm, humid weather. Improve airflow by thinning crowded plants and water at soil level to keep foliage dry, then remove heavily infected leaves. If it’s spreading, spray with a labeled potassium bicarbonate or sulfur product and reapply as directed on the label.

How often should I water Cosmos bipinnatus ‘Sonata Carmine’ during active growth?

During the main growing phase (from when plants are established until mid-bloom), keep the soil evenly moist but not soggy—aim for about 1 inch of water per week, adjusted for heat and rainfall. Water deeply when the top 1 inch of soil feels dry, since cosmos tolerates brief drought but suffers if roots stay wet. Avoid frequent light sprinkling that keeps the foliage damp and increases mildew risk.

How can I tell when Cosmos bipinnatus ‘Sonata Carmine’ is ready to harvest?

Cosmos flowers are ready for cutting about 60 days after sowing and when the flower heads are fully open with petals in their final color and a firm center. For best vase life, harvest early in the morning and cut stems just above a leaf node to encourage branching and more blooms. If you’re harvesting for seed, wait until the seed heads are dry and tan before collecting.