I’ll add another peony story here. A few years ago I was charmed by a potted tree peony at a garden shop that sported an enormous, crepe-like pink flower. It was labeled “Yachiyo Tsubaki”.
I had tons of trouble with that plant. It was grafted to an herbaceous peony, and it was a constant struggle to keep the herbaceous one from overtaking the whole plant.
But I really liked the flower, so I bought another, from Songsparrow. But that’s not the same plant. The one I bought originally had enormous single blossoms, and the one from Songsparrow has large double blossoms. It’s a fine peony, but not what I was looking for. fwiw, pictures on the internet suggest that “Yachiyo Tsubaki” is what Songsparrow sent me, and the one I bought impulsively was mis-labeled.
Anyway, three years ago, I transplanted the thing, and noticed that there was a bit of root emerging from the tree peony stem. So I conducted surgery and removed herbaceous root. Only I didn’t get it all, and damn, it’s more vigorous than the tree peony… so two years ago I tried again, very aggressively. Last year it didn’t look great, but it survived and even had a flower. Then, this spring, I found that the entire part above the ground died over the winter.
But hope springs eternal! Today I saw that there are sprouts coming from underground. And I’m pretty sure these are tree peony sprouts, not the herbaceous one. So today I attacked the grass growing around it, gave it some fertilizer, covered the earth with newspaper, and covered the newspaper with mulch, keeping it away from the stems. And surrounded the whole thing with a cage to protect it from deer.
You should be able to grow a tree peony, the herbaceous roots are only there to give the tree some time to form their own roots but I guess they can take over if the conditions are right. Good luck I hope it grows for you.
Out of curiosity, do you know why it’s so common to graft tree peonies to herbaceous roots? Are they otherwise very hard to propagate?
The one from Songsparrow was a dinky little thing when it arrived, but at least I haven’t had to constantly fight it and trim back unwanted herbaceous growth. I don’t think I looked to see what’s underground, but it’s supporting the tree peony top, whatever it is.
They apparently graft them to give the tree peony roots from which to feed until they can create their own root system.
Itoh peonies are the best of both worlds. They are a cross between a herbaceous and a tree peony. They flower like the tree peony but behave like the herbaceous. This allows for those in colder zones to grow the beautiful flowers. One of the most beautiful Itoh IMO is Bartzella, a lovely deep yellow.
I seem to have acquired some infection that kills tree peonies. At least, the rockii is doing very poorly, and gets smaller every year. I don’t recall what happened to the seedling, but it probably died.
The peony from Song Sparrow is fairly far away, and it is planted in shade. It’s certainly not growing fast, but seems okay. The impulse purchase may have caught the bug, though. Or maybe it’s just suffered in this year’s drought. I do seem to have finally removed the aggressive herbaceous root, though, so it will live or die as a tree peony.