Sonata Mix

Cosmos

Zone 2b Save Garden

🌱 60d to harvest Upright

Feathery, airy blooms open like living confetti—silky petals in a joyful mix of warm sunset pinks, rosy reds, and sunlit golds, e…

Crop Dates

Milestone	Date
Start Indoors	Direct Sow
Last Frost	May 15th
Transplant / Sow Outdoors	May 15th
Harvest Begins	Jul 14th
Harvest Ends	Aug 25th

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

Recommended Companions

Magellan Coral Zinnia

Taishan Yellow Marigold

Zahara Starlight Rose Zinnia

Lemon Gem Marigold

Red Gem Marigold

Inca II Marigold

Frequently Asked Questions

What pest or disease most commonly affects Cosmos bipinnatus, and how can I control it?

Cosmos bipinnatus is frequently troubled by aphids and by powdery mildew in humid spells. Check the undersides of leaves weekly and spray a strong jet of water or use insecticidal soap when you first see colonies; remove heavily mildewed leaves early to slow spread. Ensure full-sun airflow and avoid overhead watering so the foliage dries quickly.

How often should I water Cosmos bipinnatus during the main growing phase (after it establishes)?

Water to keep the soil evenly moist for the first week or two after germination, then shift to deep, less-frequent watering. During active growth, water about 1–2 times per week depending on heat, aiming for soil that’s slightly dry on top but not bone-dry underneath. In full sun, avoid daily shallow watering—Cosmos performs best when roots are encouraged to reach deeper moisture.

How do I know when Cosmos bipinnatus (Sonata Mix) is ready to harvest for cut flowers?

Harvest when the flower heads are fully open and brightly colored, with the center disk floret area clearly visible. Because Cosmos bipinnatus matures in about 60 days, begin cutting regularly once the first main blooms open, and continue harvesting every few days to trigger more branching and new buds. Cut in the morning and trim stems so they’re ready for a vase immediately.

Feathery, airy blooms open like living confetti—silky petals in a joyful mix of warm sunset pinks, rosy reds, and sunlit golds, each flower held on sturdy stems for a long, graceful display. Sonata Mix forms a tidy, upright plant with fine, fernlike foliage that makes every blossom look even more luminous. Ideal for fresh cut arrangements and vibrant garden borders, it’s a pollinator favorite that brings constant color from early summer into fall.

Sowing Tips

Transplant Conditions

Wait until soil reaches 60°F and nights stay above 50°F before moving outdoors.

Expert Note

For best cut-flower stems, sow shallowly (or direct sow), keep evenly moist until established, then thin for airflow and feed lightly after flowering starts.