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Cosmos – Sulphur Klondyke Orange


The Sulphur Cosmos do well in hot, arid climates.  It is native to Central America and can grow in temperatures up to and above 100° F.  The Cosmos sulphureus has a smaller flower than the Cosmos bipinnatus species.  This flower will bloom later in the season than many others.  When located in parched climate areas it can be planted in the fall.  In colder, more moist climates wait to plant this seed until spring when the ground warms up.  Otherwise, the seed will sit dormant in the ground and rot because heat is a necessary precursor to germination for this species.  In the Northwest US we wait until May to plant the seed for this species.  All Cosmos attract birds and make good cut flowers.  This flower does better if planted in soil that is more infertile.  Fertilizing it will cause overgrowth and instability.  It does not need to be heavily managed and can sustain itself when neglected.  It will survive if started indoors but will do better if it is planted directly outside.

**For larger quantities than listed for sale please contact us for availability and pricing.

The broadcast rate for seeding is 70 – 87.5 pounds per acre.

The seed drill rate for seeding in rows is 35 pounds per acre.

Purchasing Options PriceQuantity
Small Packet $2.50

Covers approximately 5 square feet.

10 Gram $3.00

Covers approximately 25 square feet.

1/4 Pound $12.00

Covers approximately 310 square feet.

1 Pound $27.75

Covers approximately 1,240 square feet.

Scientific Name

Cosmos sulphureus

Product Type







Introduced species



Germination Time

7-21 days

Planting Season


Bloom Season

Spring, Summer, Fall

Weeks to Bloom

9 to 10 weeks


3 to 10

Seeds Per Pound


Seeding Rate (lb./acre)



Nectar, Pollen


Bats, Birds, Butterflies, Honey Bees, Native Bees


The Sulphur Cosmos does well in hot, arid climates

Light Requirement

Full Sun

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