Pruning Dahlias

Dahlias are planted to be the centerpiece of many gardens, so why not make them even more show stopping? Properly pruning your dahlia plants will produce more and larger blooms. It may seem daunting, but it will ensure you have a healthy, happy, and beautiful plant all season long! The best part is, it’s easy. You need only prune them once a season for best results. 


When to Prune Dahlias

The best time of year to prune your Dahlias will vary depending on the climate. Early in the plant’s growth is considered the best time to prune, and you only should do it once. After planting the tubers, wait for the plant to have 3-4 sets of leaves shooting off the sides of the main stem; the plant should be about a foot and a half tall at this time. At this point you should cut or pinch the main stem off above the leaf sets. It may seem scary or counterproductive, but if you fail to prune your dahlia you may end up with a spindly and underproductive plant. They are fast growing plants, and pinching the plant like this will create a bushier and more prolific plant. 

Once the plant is established, you may also need to prune flower buds. Sometimes Dahlias will overproduce buds, and the plant can’t sustain them. If you want to ensure you get the best blooms, you may need to pinch buds off. Every plant and environment is different, so this technique is open to interpretation. If you notice your plant is producing many blooms, but they aren’t as impressive as you think they should be, try culling blooms. Deadheading is also a beneficial practice for many flowering plants. Removing the expired blooms keeps the environment free of disease vectors as well as open for new blooms. The plant will redirect resources to new blooms instead.


Why Prune Dahlias

Dahlias should be pruned so the plant can reach its fullest potential. Creating a thicker, bushier plant through cutting the main stem allows the plant to physically support itself and its blooms. Dahlias are a fast-growing plant. The practice of cutting back won’t hinder the growth or progress of your plant. Culling buds and deadheading are equally important practices. They encourage new flowering and rejuvenate the plant. Proper pruning keeps the plant directing its resources where they need to go.


How to Prune Dahlias

Step 1 - Identify your plant is ready for pruning

Remember, this can vary depending on climate. Pinch back the main stem when your plant is at least a foot and a half tall with 3-4 leaf sets.

Step 2 - Make the cut

When pruning anything in the garden you must make sure you are using clean utensils. Dahlia stems aren’t overly tough and can be pinched off with your fingers. If you prefer to use scissors, try and clean them often to keep diseases from spreading around your garden. Identify the area of the main stem directly above the first 3-4 leaf sets, and cut.

Step 3 - Maintenance prune at your discretion 

There is no specific time to cull extra flower buds or deadhead. As you water or spend time enjoying your garden, take just a moment to inspect your plant. Are there many blooms, but they’re all a little underwhelming? Cull some flower buds with scissors or your hands. Are there many dead or dying flowers? Deadhead them. 


Dahlia Pruning Tips

  • Pinch out the main stem early
  • Monitor your plant for overproduction of buds
  • Deadhead or pinch buds off when appropriate  .
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Author Chris Link - Published 01-24-2023