I am about to plant out my dahlias grown from tubers which have now plenty of shoots. Should I pinch out the tops of some shoots to make the dahlia more bushy?
It depends if you want a bushier plant with smaller flowers, or a taller plant with big flowers.
On a recent GW Monty cut off a side shoot at soil level and replanred it in a small pot to get another plant.
To pIant out dahlias, I would wait until the night temp is consistently around 8-10c. Then it is safe. Yes - pinch out the tops of dahlias when they are about 9" high. This strengthens the main stem and helps with stabilizing the plant in windy conditions, as well as supporting large flowers. It also provides more stems with more flowers!