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Purity Cosmos

Pure white. A classic summer flower having large 4" to 6" blooms on 3 ft. to 4 ft. tall stems. The foliage is finely cut, and the plants branch out and bloom profusely and continually. 

100 seeds




Cosmos bipinnatus


Germination: 7-10 days

Germination Temperature: Optimum soil temperatures 70-75ºF.

Seed Planting Depth: Sow ⅛” deep

Starting Indoors: Start indoors 4-6 weeks before the last frost. Provide 70-75 ºF soil temperature. Transplant after the last frost,12-18” apart.

Sowing Outdoors: Direct sow outdoors after the last frost, sow a few seeds every 6", thin 12-18" apart.

Growth Habit: Upright, branching

Height and Width: 36-48” by 24-36”

Spacing: 12-18” apart

Light Needs:  Full sun

Soil Needs: Poor to average, well-drained, tolerates dry soil

Approximate days to flower from seed: 75-90 days

Uses: Cut flowers, flower beds, containers, wildflower and cottage gardens, attracts butterflies and beneficials, 

Care: Deadheading prolongs flowering, staking tall plants helps keep them upright when the plant is full of blooms. Self-seeds.


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Customer Reviews
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A Pinetree Garden Seeds Customer
Perfect Flower

This was one of my favorite flowers to add to floral arrangements. There is something magical about a white flower, and this variety did not disappoint! Plentiful puffs of white flowers all season long.

Janice N.
United States
2018 spring garden

Becuse of cold wet weather in Ohio in April and May, I was late getting my seeds planted so I cannot give a review on the performance of your seeds. I can say that I have been very happy with your seeds in previous years and also pleased with your staff. I received the seeds timely and everything I ordered was delivered. Jan Nicodemus

Georgiana C.
United States
Pine tree seeds

I have not planted any of this years seeds, but in past years, I received my seeds, planted when season developed, and have had great success with everything I have gotten from Pinetree Garden..they Ha r provided great service. Easy to order. Most of what I grow comes from Pinetree Gardens, with only a few exceptions that are not available.