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Science-based gardening information for Colorado communities from CSU Extension, Denver Botanic Gardens, and Green Industries of Colorado.

1005 – Annuals   arrow

What are annuals?

Annuals are the “color stars” of the garden. Plant them where you want easy-care flowers to bloom all summer long. Annuals are plants that grow and bloom for one season. Some of them — like marigolds — grow, bloom and go to seed all in one season. Others — like geraniums — are really perennials that just aren’t hardy enough to survive the winters.

When can I plant annuals?

The delightful colors of annual flowers are enhanced by Colorado’s warm days and cool summer nights. This combination of unique weather conditions gives us a huge range of types and varieties of annuals to choose from. You can plant most annuals any time during the spring, summer or fall, and they’ll bloom continuously until the first frost in fall. Most annuals are planted after the last frost in spring. Of course, the time the first frost occurs varies within Colorado, but it generally occurs between the tenth and fifteenth of May along the Front Range.

Can I plant annuals when it’s still cold?

By learning a little about different flowers, you’ll find that some–like petunias–tolerate cool conditions better than others, and some–like pansies–even survive frost. Some pansies can be planted in the fall to achieve color all fall, winter and spring. Others — like vinca — are heat lovers only.

For “Combining Colors” refer to message number 1113.

For more information about annuals, see the following Colorado State University Extension resources(s).

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