What I Learned Today – Tree Peonies are Grafted!

About a month ago, as the leaves on my yellow tree peony (planted in 2019, on the label it’s called Poaeonia suffruticosa yellow) were expanding and flower buds getting ready to burst open, I noticed a few leaves that looked quite different. Following the stem down it appeared to come from the base of the tree peony ‘trunk.’ How strange, I thought. Then it dawned on me – it’s a graft! Tree peonies must be grafted onto a different peony root stock, much like apple trees and hybrid roses are.

My first thought was to prune off this shoot as it would siphon resources from the ‘tree’ and make a generally untidy looking plant. But at the tip of this new shoot was a bud, and it appeared to be expanding as it should, with a few ants crawling over it as they do with healthy peony flower buds. So I let it grow, and late last week it opened into a pleasant pink single peony flower.

I’ve now read a bit more about tree peonies and know that many are indeed propagated by grafting a bit of existing tree peony branch (with a bud or two) onto a bit of herbaceous peony root stock (a bit without any eyes) so that the herbaceous root can act as a ‘nursing root’ until the tree peony bit can develop and grow its own roots. The trick, it seems, is to plant the new tree peony deeply, at least three to four inches deep (8 – 10 cm). So I likely planted mine a bit too shallowly, and I will, indeed, prune off this sucker, below the soil line, and add a bit more soil around the base of the main trunk.

Interesting to find in my research that although the plant label didn’t mention it, my yellow tree peony is probably the result of hybridization done by the Frenchman Victor Lemoine in the 1920’s and 1930’s; the plant label should likely have had the moniker lemoinei somewhere in it. Before then the flowers were purple, pink and white.

I wonder what root stock was used to graft my tree? It looks so similar to the Bowl of Beauty herbaceous peony now in bloom elsewhere in my garden…