Rubenza

Cosmos

70d to harvest

Velvet-soft petals unfurl in a luminous spectrum, with Rubenza’s blooms carrying a rich, warm presence that seems to glow from within. Expect airy, fernlike foliage and long, sturdy stems that hold their poise in the vase, making each flush feel abundant and effortless. A pollinator magnet from the first open flower to the last, Rubenza delivers showy, daisy-like color for seasonal bouquets and garden borders alike.

Crop Dates

Milestone	Date
Start Indoors	Feb 13th
Last Frost	Mar 6th
Transplant / Sow Outdoors	Mar 13th
Harvest Begins	May 22nd
Harvest Ends	Nov 26th

Crop Details

Trait	Value
Days to Maturity	70
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)	7

Recommended Companions

Lemon Gem Marigold

Queen Lime Blush Zinnia

Jewel Mix Nasturtium

Marigold Marigold

Alaska Mix Nasturtium

Magellan Coral Zinnia

Frequently Asked Questions

What’s the most common pest or disease problem for Cosmos bipinnatus (Rubenza) and how can I fix it?

Cosmos bipinnatus commonly suffers from powdery mildew in humid weather, shown as a white, dusty coating on leaves and stems. Improve airflow by spacing plants well and watering at the soil line; remove heavily affected leaves early. If it keeps spreading, spray with a potassium bicarbonate or horticultural oil product labeled for ornamental Asteraceae and repeat according to the label every 7–10 days.

How often should I water Rubenza Cosmos bipinnatus during peak growth?

During active growth (once plants are established and blooming), keep soil consistently lightly moist but never waterlogged—aim for about 1 inch of water per week depending on heat and rainfall. Water deeply when the top 1–2 inches of soil dry out, because Cosmos bipinnatus tolerates brief drought better than soggy conditions. Avoid frequent shallow watering, which encourages weak growth and mildew.