I found this recommendations below on a Chinese website. ChatGPT translated it. I know that tree peonies are often pruned hard in Asia. I was surprised that they recommended to keep only five stems for Necklace wit Precious Pearls, which is semi-spreading. Five stems for Japanese varieties, which are usually upright, sounds about right, but I would expect that lower semi-spreading and spreading varieties are allow to keep more stems Here is the translation:

"Pruning: In the year of planting, it's advisable to perform a heavy pruning. In spring, after sprouting, leave around 5 main stems and remove the others to concentrate nutrients, resulting in larger and more vibrant flowers in the second year. In the autumn and winter seasons, while also tending to garden cleaning, trim off dried flower stems and thin, non-flowering branches. For potted peonies, prune them to achieve the desired shape."

Do you prune your tree peonies? How do you prune them? Can smaller number of branches really produce bigger flowers? Please advise.

An interesting question! Have never seen it advised to prune tree peonies, I've only removed dead stems.

Hi Jasmin - for what it's worth I just cut tree peony stems back to one node above an obvious bud in case the winter is mild enough for those to leaf out in the Spring. Mostly it is cultivar dependent as to how winter hardy those buds are but either way, I'm happy with the size of my flowers and see no reason to remove potential flowering stems for a slight chance they will be bigger if there are fewer stems

I just cut back dead, declining branches. That in and of itself seems to encourage new growth and resilience.