Cosmos! Best late summer and fall flowers for our area

Very few carefree flowers of summer delight so many people as the simple Cosmos. Their name evokes their appearance in the garden since the word Cosmos comes from the Greek word meaning orderly, beautiful and balanced.

Cosmos plants are members of the Asteraceae or Aster and Sunflower plant family and are native to Mexico, Central America and the southern US.

With new breeding, the 25 species range from tall and willowy plants to spreading and branched annuals. The flowers are single and double, and come in bright colors from yellows and oranges to pinks and reds plus white. The flower shapes include saucers, bowl, open cup, and tubular.  Most of the flowers measure 2-inches across though some of the side branching blooms are smaller.

In Mexico, Cosmos were known to be grown by Spanish priests

Cosmos atrosanguineus
who gave them the name in recognition of their balanced petals. The priests claimed that they exuded cosmic beauty and harmony.

Cosmos atrosanguineus or Chocolate Cosmos is a zone 10 tuberous perennial that is sometimes available as a container plant in nurseries. The more common Cosmos are rarely available in containers or six-packs, but they are easy to start from seed when the soil is 60-80-F in the spring.  Seeds are available from

Some gardeners rely on Cosmos for their fall flower beds. The sweetly scented blooms provide nectar for butterflies, skippers, bees, hummingbirds, and hover flies. The flower stems are long enough to use in small bouquets and the flowers last for a week in the house.


Cosmos likes decent soil and lots of sun but no fertilizer and minimal water. They should be planted at least a foot apart for good air circulation. Otherwise, they are very easy to grow.
The two most common Cosmos are the annual Cosmos sulphureus and Cosmos bipinnatus.
Cosmos sulphureus has long narrow leaves and the flowers are orange and yellow. Cosmos bipinnatus, the one most commonly planted, has feathery leaves that resemble dill or ferns. The flowers range from pink and white to red and bi-colors.
Native to the Americas, Yellow Cosmos (Cosmos sulphureus), can grow 4 to 7 feet tall with colorful flowers and yellow centers. Some of the shorter varieties available include: Crested Red, Ladybird Dwarf Red, Ladybird Dwarf Orange, Ladybird Dwarf Lemon and Klondyke Mix.
The Ladybird series mature at 2-feet tall so if shorter plants fit in better with your garden, choose those. Ladybird Dwarf Gold is only 12-inches tall and the seeds are available from A collection called Little Ladybirds is available from Renee Seed at
Cosmos bipinnatus
Cosmos bipinnatus varieties are the ones with fennel-like foliage and bowl or saucer shaped flowers that can grow to 3-inches across in white, pink and crimson. (Pinnatus means feathered or feathery.) The plants mature at 3 to 5-feet tall and 18-inches wide.
Daydream is white with a pink center, Picotee is white with crimson margins on each floret, and Sea Shells is carmine-red, pink or white. Sea Shells has tube-shaped petals that radiate from the center, often in two colors. The Sensation Series have very large flowers on 3-foot tall plants.
The dwarf Cosmos bipinnatus include the Sonata Series (Sonata White, etc.) that grow to a foot tall and wide in whites, pinks and reds. (Available from and
Wildseed Farms ( offers a dozen seed varieties and a 14-variety combination pack called “Can’t Make up My Mind” for $15.25.
Plant the seeds 1/16th inch deep on raked soil. Seeds will come up within one-to-three weeks. Both Cosmos sulphureus and Cosmos bipinnatus bloom from early summer through late fall. In order to have continuous bloom, spent flowers have to be removed and the entire plant can be pruned or sheared to eliminate seed pods.


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