2012 Peony Experiments - Cutting Back Dead Flowers

I usually don't get around to cutting back dead flowers on my peonies. The past couple of years I have just left them to fend for themselves until the entire stem dies back. That way I would leave the flower head intact so that seeds could develop. However I have noticed quite a bit of fungal disease, and I wondered if it had any correlation to leaving the spent bloom on the plant. The flower type really seems to make a difference in this. The single and semi-double type flowers that shed their petals easily do not seem to have as much fungal disease as the more full double flowers that seem to hang onto their petals. Also I have noticed that dead petals that have fallen onto foliage below actual contribute to additional fungal growth that otherwise may not have developed. It seems the dying petals create just the right environment (more moist and warm) that the fungus needs to develop.

Dried Peony Petals on Foliage


Fungus on Peony Foliage
Over time I have been able to better recognize which seeds pods actually have developing seeds in them. So this year, I have started cleaning up my full double flowered peonies to remove the spent blooms. I also have 2 peony bushes of a white double peony that are the same variety. I decided to cut back the spent blooms on one of them, but not the other. I will check the amount of fungal disease later in the season. I also plan to cut down the dead foliage on the same one I cut back the flowers on and leave the dead foliage intact on the one I didn't cut back the flowers on. So we shall see how much difference it makes in the amount of fungus on the plants this fall and next spring.

Peony Spent Blooms Not Cut Back


Peony Spent Blooms Cut Back