I am sorry I cannot be specific as I have not grown this particular peony, but I have seen my Mother-in-law's peony grow so large it flops over (in fact, every year it does this). Hope this helps.

Planto

I grow mine through a grid to give the stems support, especially the double flower varieties. I am surprised at how early in the year you have the problem. I never fertilize my peonies, other than the adding of compost around the plants. Al

Molly can take 4 years or more to become happy where planted. Which is one of the reasons they are priced so high if the real thing.

If you mean Paeonia Mlokosewitschii: it ALWAYS blooms briefly, not only last year or any other year. Mine have never needed any support, but as they usually are seed propagated , you never know what an individual plant will be like.
Actually, majority of single peonies usually blooms briefly. The record in my garden belongs to a variety called Flame, where the whole clump bloomed for 2 (two) days.

So, does any of you have any Molly The Witch to trade or sell? I have an unknown single yellow that was given to me and I do not know if it is Molly The Witch. It is budding and will try to get back here with pictures. My peony called Flame blooms more than 2 days. Looks like I need to post some pictures. Stay in touch. Peony addict has 140 named varieties of peonies, always looking for one I do not have.

Looks like no one has this peony. here is the picture of one that was given to me several years ago, but the picture does not do it justice.Does anyone have any to sell or trade?

Looking for one of these in the spring found an awesome specimen at Cady Falls nursery in VT

Is your Molly in the shade? Could it just be getting leggy because it wants more sun?