Cosmos flowers are an annual flower grown throughout North America. Originating in Mexico, there are over 20 varieties, each with a unique color and size. Cosmos flowers are easily grown and require very little care, making them an excellent flower for novice gardeners. In this article, we will describe the cosmos flower and explain how to grow these unique flowers in your garden.

pink cosmos flower

What Is the Cosmos Flower?

Cosmos flowers are annual plants that bloom continuously throughout the summer and fall. The flowers are typically 2 to 5 inches and have round centers surrounded by broad pedals. They are part of the same family as the sunflower and the aster. There are over 20 varieties of cosmos flowers with a range of sizes and colors. The smallest varieties may only grow twelve inches tall, while the largest ones may grow up to seven feet.

Cosmos flowers will continue producing flowers throughout the summer and fall. The flowers can be trimmed from the plants throughout the season, promoting new flower growth. The flowers are often used in bouquets or are dried for potpourri. They also attract a variety of birds, bees, and butterflies, including Monarch butterflies.

Main Varieties of Cosmos Flowers

Cosmos flowers are available in many sizes and colors. All cosmos flowers are part of the family Asteraceae. There are three species of cosmos flowers. All three species produce flowers that are commonly used in bouquets and attract butterflies, birds, and bees.

  • Cosmos bipinnatus: Also called the Mexican Aster, these plants typically grow 2 to 4 feet tall. They produce pink or purple flowers.
  • Cosmos sulphureus: Also called the sulphur or yellow aster, these plants can grow 1 to 7 feet tall. They produce yellow, orange, or red flowers.
  • Cosmos atrosanguineus: Also called the chocolate cosmos, these plants grow 1 to 2 feet tall. They produce dark red, brown, or black flowers. They are also known to produce a slight vanilla fragrance.

How to Grow Cosmos Flowers in your Garden

Cosmos flowers are considered to be extremely easy to grow and require very little maintenance. They are easily grown from seeds and if flowering plants are allowed to produce seeds, they often reseed themselves for next year’s growing season. Smaller varieties of cosmos flowers can also be grown in a container. To grow these flowers, follow these simple steps

  1. Choose a location that gets full sun. Cosmos flowers grow best when they receive direct sunlight for most of the day.
  2. Plant seeds directly in the garden after the last frost is expected. Seeds should be planted approximately one quarter inch deep. There are two common ways of planting seeds: 1) dig a shallow trench, place seeds inside approximately 12-18 inches apart, and cover with soil, or 2) scatter seeds on the surface and rake them into the soil. Once the soil temperature is approximately 70 degrees Fahrenheit for one week, seeds will begin to germinate.
  3. Avoid using gardening soil and fertilizer. Cosmos flowers do not require high quality soil or added fertilizers to grow. They only require soil with good drainage and direct sunlight. From seeds, plants will mature after about 7 weeks.
  4. Trim the plants to encourage new flower growth. Cosmos flowers will continue to bloom until the first frost. If left unattended, flowers will produce seeds. To promote new flower growth, the plant should be trimmed to roughly half its height once seeds begin appearing,.
  5. Collect seeds for next year. The seeds of the cosmos flower can be collected and planted in the following year. Alternatively, if the seeds on the plant are left alone, they will fall to the soil and reseed themselves for next year.

Cosmos flower seeds can also be spread in open fields and grown as a wildflower.


The cosmos flower is easily grown by novice and professional gardeners alike. Their range of sizes and colors make them a versatile flower that can add color and variety to any garden. Because cosmos flowers bloom continuously throughout the summer and fall, they are a perfect flower for bouquets and to attract bees, butterflies, and birds throughout the year.


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