Cosmos bipinnatus

Cosmos bipinnatus

This plant is not native to Canada, but is a very popular annual. With finely cut leaves, showy flowers and a long blooming season, Cosmos are quite hardy, blooming profusely from early or midsummer until fall, depending on varieties. This Mexican native looks striking when planted in masses or filling out mixed plantings.

Cut flowers last more than a week in fresh bouquets. Saucer-like blooms stand out against a backdrop of fine, airy foliage. Cosmos also attract birds, bees and butterflies.

The word “Cosmos” comes from the Greek word meaning “harmony and ordered universe.”

Ideal choice for beds, borders, and cutting gardens. Excellent backing plant for mixed borders.

Cosmos are freely flowering annual plants in the asteraceae or sunflower family. They are super easy to grow. If you’re looking for a flower that will stay in bloom for months and can be grown easily by scattering seeds, cosmos are a great choice.

Video on Cosmos bipinnatus

Planting Cosmos bipinnatus

Sow seeds directly in soil after the threat of frost has ended. Young plants may be transplanted from pots at this time. Rich soil will encourage foliage rather than blooms, so it is not necessary to make any special soil preparations.

Companion plant suggestions include Baby’s Breath, Coreopsis, Russian Sage, Daisies, Asters, Black-eyed Susans, many more choices.

Caring for Cosmos

Cosmos grow easily in beds, and they make great cut flowers. When established, the plants can handle drought, poor soil conditions, and general neglect. They even self-sow. May reseed, for a surprise return next season, if dried flower heads are left intact.

It is happiest in Tolerant of most soil pH levels, but grow best in neutral to alkaline soils.

In terms of water, Cosmos needs Tolerates drought

Pruning Cosmos bipinnatus

Remove spent blooms to prolong flowering.


Susceptible to stem canker, powdery mildew, aphids, flea beetles or gray mould. These are easy to control with insecticidal soap, or by spacing plants accordingly to ensure quality air flow.

Cosmos plants were brought back to Madrid in the 16th century by Spanish explorers. Seeds were brought to England in the late 1700’s and made their way to the United States around 50 years later.