IN THIS GUIDE
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:
- Identify when to pinch out – typically this will be when your plant has grown to 30-40cm in height.
- 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.
| Difficulty | Easy |
| Equipment Required | Secateurs or snips |
| When To Deadhead | May, June, July |
When To Pinch Out
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 –
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.
Don’t worry about pinching out this new growth.
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.
