Horticulture Magazine

Remember To Pinch Out Your Dahlias: It Will Help To Promote Better Growth

Pink flowering dahlia plant growing outside
By ED BOWRING
Ed Bowring, BSc, DipSTH, Horticultural Therapist & Gardener

Ed is a horticultural therapist, professional gardener and writer. Ed has a BSc in Occupational Therapy from Coventry University and a Diploma in Social and Therapeutic Horticulture (DipSTH) via Thive, the RHS and Pershore College. Ed runs a community kitchen garden in West Sussex, where he leads horticultural therapy sessions.

/ Updated November 14th, 2024
Reviewed By DAN ORI
Dan Ori, MCIHort, Horticulturist

Dan has over 27 years’ under his belt caring for plants and gardens. Working as a Horticultural Instructor and Consultant, he draws on a diverse range of experience that includes working as a Head Gardener, Tree Surgeon, Garden Centre Trouble Shooter, and writer of academic papers. Dan has a Level 3 Diploma in Horticulture and is currently a candidate for the RHS’s most prestigious award – The Master of Horticulture.

/ Meets Our Editorial Guidelines
Contributions From ELAINE PATULLO
Elaine Patullo, Owner of Dachshund Dahlia Plant Nursery

A dahlia lover based in Scotland, Elaine owns Dachshund Dahlia Plant Nursery, a specialist seller that offers some varieties of dahlias for sale that are not commonly found in the UK.

, JACK GOTT
Jack Gott, Owner of JRG Dahlias

Jack is the Owner of the specialist plant nursery JRG Dahlias, with over 50 years experience of growing dahlias. He’s previously created content for The National Dahlia Society and is a judge in their Cumbria district.

, JUNE NASH
June Nash, Secretary for the National Dahlia Society

The current Secretary for The National Dahlia Society, June is known for her extensive dahlia knowledge and has even been recognised by the American Dahlia Society for her contributions.

, DAVID HALL
David Hall, Director of Halls of Heddon

David is the Director at Halls of Heddon, which is a dahlia nursery established in 1921. David has a large following on social media and runs a YouTube channel, where he shares updates on the dahlias he grows each year.

, GEORGIE NEWBERY
Georgie Newbery, Common Farm Flowers

After establishing Common Farm Flowers with her husband in 2010, Georgie Newbery has become one of the UK’s most reputable flower farmers. Georgie runs workshops when she isn’t busy arranging floral bouquets and also regularly shares tutorials on YouTube. She is also the Author of several books, including The Flower Farmer’s Year and Grow Your Own Wedding Flowers.

Dahlias are a large group of stunning perennial plants widely grown here in the United Kingdom, as they can flower from mid-summer right up until the first frosts at the onset of winter.

“Dahlias are easy to grow and have wow factor, and, flowering from July to the first frosts, they are the most giving of flowering plants,” shares Florist Georgie Newbery.

Available in a dazzling array of shapes, sizes and colours from cool whites to vibrant reds, there is a dahlia to suit every garden.

Why Pinch Out?

“Pinching out is useful, especially for promoting more flower heads,” Elaine Patullo from Dachshund Dahlias puts it simply.

Dahlias are easy to care for and will often grow well enough if left to their own devices.

However, pinching out (removing the central growth tip when young) will encourage the plant to develop into a more sturdy and bushy plant and produce more flowers.

Pinching out dahlias is a straight-forward process and is applicable to all the different types of dahlias available to grow:

  1. Identify when to pinch out – typically this will be when your plant has grown to 30-40cm in height.
  2. Pinch out the top growth – the central stem of the plant.

Pinching out should be undertaken early in the summer before the plant has matured and begun flowering.

This process is explained in more depth below.

DifficultyEasy
Equipment RequiredSecateurs or snips
When To Deadhead May, June, July

When To Pinch Out

messy foliage of dahlia plant that is growing well during spring

Dahlias should be pinched out in the early stages of their growth when the plant has grown to about 30-40cm high.

“If you pinch your dahlia out once the plant has 3 sets of leaves, this will help the plant to bush up and send more lower leaves up,” explains Jack Gott, owner of JRG Dahlias.

Here in the UK, this tends to be around May to July, depending on whether the plants have been started off undercover in a greenhouse or planted directly outside.

“If you are growing from a tuber and have several shoots appearing this is not strictly necessary unless you want a shorter and bushier plant,” says June Nash, secretary of The National Dahlia Society.

How To Pinch Dahlias

Once the dahlia plant has reached the desired size and stage, it is time to pinch out the top growth.

The material to remove or pinch out is the topmost leaf and stem growth of the central and tallest stem on the plant.

This is known in horticultural terminology as the ‘Terminal Bud’.

In the image below, this would be the central stem which is showing signs of a new bud –

the terminal bud of a dahlia seedling ready to be pinched out

This new growth only needs to be removed down to the plant’s top pair of leaves, which can sometimes mean only removing a very small amount of the plant.

“If you are growing from a small plant or rooted cutting it is advisable to pinch out the centre bud when about 4 pairs of leaves are showing,” says June.

“This will encourage the side buds in each leaf axle to grow, making a bushier plant.”

To remove, the new growth can simply be pinched off using a thumb and forefinger or a sharp and clean pair of small snips or scissors, being careful not to damage any growth on either side.

“Down on the south coast of England, I usually use the week of the Chelsea Flower Show to remind me to pick out my Dahlias (Late May),” shares Horticulturist Dan Ori.

many new buds of flowers on a large dahlia plant

Don’t worry about pinching out this new growth.

yellow flowering dahlia with dark green foliage growing outside

It may delay flowering for a short time but it won’t stop the plant from growing, in fact, it will do the opposite and can encourage more stems to grow and more flowers to bloom.

David Hall, from dahlia nursery Halls of Heddon, says that you should be rewarded in around 1-2 months for pinching out your dahlias, with larger varieties taking longer to get to their best.

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