How to pinch dahlias?

Topping dahlias involves pinching or clipping off the growth tip, the topmost bud of the main stem, as soon as the plant has developed four to six pairs of leaves. This is important to ensure that the dahlia branches out instead of growing straight upwards. The result? A beautiful garden full of colourful dahlias!

In this blog, we tell you how to top dahlias for an impressive result in your garden or border.

What does topping dahlias mean?

Topping simply means consciously cutting or pinching off the main stem of your dahlia. It's quite simple: you remove the growth tip, the topmost part of the plant, where the stem is still soft. This stops the plant from growing upwards and directs all its energy to the side shoots. More side shoots mean more branches, more buds, and ultimately many more flowers. You can control the growth of the dahlia much more than you might think!

Why should you top a dahlia?

A dahlia that isn't topped simply grows straight upwards. It will then produce one main stem with a few flowers. Beautiful, of course, but for a colourful collection of dahlias, you'll want the plant to branch out. Two side shoots become four, and four then become eight.

More branching means more flower buds and a longer flowering period. This way, you can enjoy your blooming garden full of dahlias even more and for longer.

Topping dahlias: how to do it

Generally, wait until your dahlia has formed four to six pairs of leaves. For most plants, this is sometime in May or June, depending on when you planted them outdoors. The plant will then be firmly established and have enough energy to recover from the topping. Then:

• Find the main stem and follow it up to the top growth tip.
• Pinch off that growth tip with your fingers or cut it off with scissors.
• Then let the plant do its work. Within 2 weeks, you'll see the side shoots.
  

When should you top dahlias?

You usually top your dahlia when the plant is about 20 to 30 centimetres tall and has at least 2 to 4 pairs of leaves. For most dahlias, this moment is sometime in May or early June, depending on when you planted them outdoors and how warm the spring is.

Bulbs4You Tip: Don't wait too long. The larger the plant, the less energy will be left for the new side shoots that emerge after topping.

How to recognise spent dahlia buds?

Spent dahlia buds are very easy to recognise, if you know how to identify them. Spent buds often have a pointed shape, while new buds are nicely round and firm.

It's quite possible for a single dahlia plant to have both new and spent buds. In that case, it's advisable to remove only the spent buds and leave the new ones alone.

When should you dig up a dahlia?

Eventually, the plant itself indicates that the season is over. The flowering decreases, the stems become weaker, and as soon as the first night frost has hit the plant, the leaves and stems turn black. That is the time to take action and dig up the dahlias. We recently wrote a blog in which we explain this to you completely!

Want to enrich your flower garden with more dahlias?

Bulbs4You Besides maintaining your flowers and plants, it can sometimes be fun to add new colours and varieties to your border. At Bulbs4You, you can order the most beautiful dahlias and many other flower varieties conveniently in our webshop. Our assortment has been carefully and thoughtfully curated, selected directly from growers in the Bollenstreek. Choose from over 250 dahlia varieties.