There are a lot of small things you can do which make huge gains in your gardening, pinching out the growing tips on some plants is on of these easy wins.
For new gardeners, the idea of pinching or snipping off the top of a plant can be terrifying. Especially when you’ve put so much time and effort into nurturing and caring for that plant, so let me talk you through why you might choose to “pinch out” and how to go about it, to help you decide if it’s for you.
What is pinching out?
Very simply, pinching out is when you snap or cut the very top of the plant stem, above a set of leaves in order to encourage the plant to change its growing habit. In this case, with dahlias, when you have a plant which would naturally grow very tall with few stems which produce flowers at the end, we are encouraging the plant to grow more stems and therefore more flowers rather than just allowing nature to take its course and produce a tall plant with less blooms.
It works by activating the growth hormone in that plant stem which sends the plant into temporary overdrive in producing shoots at other points in the stem. Because we are forcing the plant to focus on growing more shoots rather than flowers, it will delay your flowering for a few weeks, but in the long run, the plant will produce a lot more blooms.
When and how should you pinch out your dahlia?
The best time to do this is when your plant is still young but strong enough to recover quickly. I choose to do this when my plant is roughly about 8 – 12 inches tall. So usually there will be 3 to 6 sets of leaves on the plant. If your dahlia is more than 12 inches tall, I’d say it’s probably too late to pinch out that stem. Dahlia stems are hollow once they mature, so cutting or pinching them once it has begun to hollow will provide the opportunity for pests or diseases to take hold.
To pinch out the growing tip, count the sets of leaves up to 3 sets and then grasp the stem right above those leaves with your thumb and index finger and fold the stem back until it snaps cleanly.
If you haven’t managed to snap the stem back close to that leaf junction, simply use a clean pair of snips of secateurs to cut the excess stem back.
There you go, you have now pinched out your dahlia, now you just wait for those blooms.