Problem with peony! Lack of watering in the summer?

[andré B]

Joakim, If you decide to dig the peonies up to replant them the best time would be end september/ october. Be very careful with the roots of tree peonies because they are very fragile in particular when freshly dug up. If I were you I indeed would separate the plants in order to give them more room but also because it could be that some grow taller than others and the effect would not be good if you would have one taller plant obscuring the smaller one.
Joakim you further mention Magnolia's growing nearby. I know from experience that few plants/trees have a more dense and superficial root system than magnolias so you are well advised to keep a safe distance between any magnolias and the peonies.

André Bourgonje

[Joakim B]

Thanks for this information André.
I will act accordingly
Kind regards
Joakim

[Joakim B]

Any thought if I need to take off the foliage from the root that the peony is grafted on?
I have a picture of it.
The new roots of the graft can also be seen.

I did some replanting even if it might be a bit to early but timing can not always be perfect.

Here is what I found the small seadling hade huge roots und just showed the tio of the iceberg and the grafted ones had roots froing from the graft (this is an older plant than the above discussed plant).

Kind regards
Joakim

[Paul T]

Joakim,

If the graft has enough roots to grow on it's own I would be removing the rootstock altogether (you can then just grow it as a second Paeony.  Technically herbaceous rootstocks for tree paeonies are supposed to be temoporary and removed after a few years.  The herbaceous rootstock continues to grow underground (I have seen huge swollen rootstocks larger than a rugby ball below the grafted plant) and can eventually rot and kill the grafted plant above them.  I think that for ideal growth the rootstock should be removed after 3 or 4 years, but the majority of people just leave theirs in place.  A few years ago a friend and I investigated a shooting rootstock on an imported grafted plant (my friend did a few bits of importing, which is a laborious process through quarantine etc here in Australia) and we were able to get a couple of plants out the rootstock, plus a big healthy plant that was originally the graft.  All grew on quite happily.  Once the grafted plant has sufficient roots it doesn't require the rootstock any more, and as I said the rootstock can become a problem in the future in some cases.

[Joakim B]

Paul
I was thinking along the line of divide the plants but I did not dare and took of the foliage and that part of the root where the foliage camefrom but left the rest of the root since I was not sure how big the roots of the tree peony were. For the older one I did not see any typical peony rhizom below ground, just the roots of the treepeony. I think that "the old roots" may actually die in some cases and be no problem but I will keep my eyes on to see if it gets any problem with the roots.
Thanks for the advice
Joakim

[Paul T]

Joakim,

I's imagine in the majority of cases the rootstock does eventually rot off, it is only in some cases that it can become a problem when it keeps swelling underground.  When we took the rootstock off the imported grafted variety we were interested in it as well as many of the Japanese rootstocks are varieties that aren't here in Australia.  It will be interesting in the future to see what the imported rootstock colouration is when it flowers.  Apparently a rather lovely purple is often used..... which is what we're hoping for!! 

[Joakim B]

Paul
My parents bought a tree peoney and it later bacame a herbaceous peony and a pink simple/single one that does not support its stems.
I hope You are luckier with your roots
Joakim

[Paul T]

Joakim,

It's still going to be fun to find out!!    Not good to hear that the graft died on your parents one.  At least if it had been a decent herbaceous they wouldn't have minded so much, but given it was a dud that is pretty disappointing!!

[Joakim B]

Paul
I think they planted to high and with a stong winter they got the gaft frozen and all what was left was the herbaceous. They never noticed when it happen only that they had a pink one where they supposed to have a nicer one. It is still there to remind us to plant properly
It is tricy that the herbaceous wnt shallow planting and the tree deep planting since they are often just called "peony".
Joakim