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We have been busy packing our favorite flower seeds and gearing up for another amazing year. Stay tuned for back in stock seeds and plants for 2025 plus over 75 new varieties!
Cosmos 'Rubenza'
Cosmos 'Rubenza'
Cosmos 'Rubenza'
Cosmos 'Rubenza'
Seed Packet

Cosmos 'Rubenza'

Cosmos bipinnatus
A fabulous deep red color of everyone's favorite summer flower, Cosmos' Rubenza' offers easy-as-pie culture, loads of blossoms, and ample pollen for bees. Not fussy about soil, just deadhead or cut for bouquets to keep the show going. Pinch once when 1' tall for increased branching and more flowers.
SKU #S624
$3.50
Currently Unavailable
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Growing Companions
Melampodium 'Showstar™'
Melampodium 'Showstar™'
Cosmos 'Rubinato'
Cosmos 'Rubinato'
Marigold - African 'Yellow Supreme'
Marigold - African 'Yellow Supreme'
Fennel 'Smokey Bronze' Organic
Fennel 'Smokey Bronze' Organic
Details
Approximate Seeds Per Packet
67
Lifecycle
Annual
Annual Hardiness
Half Hardy Annual
Mature Size
2-3.5' h x 2' w
Sun
Full sun
Soil
Regular, well-drained
Season
Summer to fall
Color
Deep red single flowers with gold centers
Features
Great Cut Flower
Heat or Drought Tolerant
Attracts Butterflies
Attracts Bees
Attracts Beneficial Insects
Notable
RHS Award of Garden Merit Winner
SOWING INSTRUCTIONS
Depth:
1/8-1/4"
Sprout Time:
3-10 days
Seed To Bloom:
8-12 weeks
Starting Indoors:
Start in pots 4-5 weeks before last spring frost. Keep at about 60-75°F.
Starting Outdoors:
Direct sow in spring, after last frost.
WHEN TO SET OUTSIDE
In springtime, after all danger of frost has passed.
PLACEMENT & CULTIVATION
Thank goodness we live in the age of the quick-blooming cosmos. Early 20th-century gardeners had to be content with a fleeting flower or two before the frost came to claim them all. Cosmos today are super floriferous midsummer to fall with reliable bloom in hot and dry weather. Pinch out stem tips when plants are 1' tall to help grow bushy, branching plants with loads of flowers. Start indoors in pots for earlier bloom and sow directly for flowering starting mid-summer. Deadhead regularly and stake early in windy areas, as the branches are quite brittle and can snap off at the central stem. Cosmos attracts numerous beneficial insects, making them a valuable addition to the borders of vegetable gardens too!
Final Spacing:
1.5-2'
Water Requirements:
Low Water Use
Watering Details:
Drought tolerant. Water regularly while establishing, then water only during dry, hot spells.
Soil pH:
Prefers acidic to neutral
Fertilizer:
Cosmos thrive in regular soil and may sprawl in nitrogen rich soils. If desired, an application of organic flower fertilizer can be mixed in around plants.
Diseases & Pests:
No major pests or diseases. Powdery mildew can be discouraged with a regular preventative application of a baking soda based spray.
When to Cut for Bouquets:
Harvest when flowers start to open to 1/2 open; best vase life before the flowers are pollinated.
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