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How to Deadhead Dahlias to Keep Them Blooming All Summer

Rachel is a passionate plantsperson, YouTuber and author living in Ireland. She grows a wide range of hardy subtropical and tropical plants.

Dahlia 'Karma Choc' in full bloom!

Dahlia 'Karma Choc' in full bloom!

How Do You Keep Dahlias Blooming All Summer?

From July, dahlias are important players in the garden display. Their large, colorful flowers really brighten up the flower border. And with simple deadheading, that color can keep on going.

With regular deadheading, dahlias will flower from July until October or November—whenever you get your first frost. The first frost withers dahlias, ending their flowering for the year.

Note how round the fresh dahlia bud on the left is. Spent blooms will be more pointed.

Note how round the fresh dahlia bud on the left is. Spent blooms will be more pointed.

How to Deadhead Dahlias

  1. Follow the stem down to the highest bud and snip.
  2. If the stem branches, snip off the spent arm.
  3. If both arms of the branch are spent, then snip to the next bud down.

How to Tell the Difference Between Spent Blooms and New Buds

If the flower is already well withered, it can be confusing to identify which is the new bud and which is the spent one. Buds are round, while spent flower heads are more pointed.

Snip off the pointed flower heads, but leave the rounded ones. In a few days, they'll open into fresh, beautiful flowers.

Don't let a few spent blooms ruin your whole dahlia display!

Don't let a few spent blooms ruin your whole dahlia display!

Why Should You Deadhead Dahlias?

We need to deadhead dahlias for two reasons. The first is to encourage repeat flowering. The second is because withered, brown flowers really, really draw the eye. Even in an extensive garden, our eye is immediately drawn to any brown spots; just a few spent dahlia blooms could ruin the whole display!

Don't let your good gardening work be undermined by the failure to carry out some simple deadheading.

More Information About Dahlias

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Rachel Darlington

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