Hi, My tree peony, which was already flopping over with the giant flower heads (I did stake it up!), has not become upright again after the heads have been removed. It did spring back up in previous years after the seed head removal. Apparently the leaves themselves are too heavy for it's skinny 'trunks'. Could I, should I give this beastie a serious prune..if so, how far down can I take it, and when? Although it has many flowers, I am wondering if it is in too shady a spot for most of the summer (when the neighbouring sumac shades it for much of the day), and is just having to reach too much. Are these hybrids better kept at 2-3 ' instead of going to what I have been told is their max height..4-5'? Thanks, Jane
Try cutting one or two of the worst ones to the ground, to start over from the base. These are often grafted on herbaceous peony roots, don't cut below the point where the tree peony scion was inserted into the herbaceous peony root (this should have been buried at planting but maybe it wasn't in this case).
Other than thinning out weaker main stems as RonB suggested, you could also prune from the top down after it has formed the axilliary buds in the leaf axils {next years leaves and flowers}. The buds should be forming this month, so pruning near months end would work. Could remove the terminal buds [next years flowers} and leave at least 2-3 buds on the lower portions of each branch, keeping in mind that you are forming next years branching pattern and flowering with the remaining buds. You just need to prune out the new buds above the desired height and can be careful not to damage the leaves as you remove the buds. The top portions above the buds will die back in the fall. As it blooms well, it sounds well situated, although they generally don't seem to like shallow root competition or too much shade. The hybrids generally seem fairly vigorous, is it yellow or a named one ? Suppose if you were to move it, the sumac might begin to sucker and cause a real mess.
Thanks both for he suggestions. As for the sumac suckering, I had to laugh. Mine needed absolutely no disturbing to stretch out the entire length and width of my garden (and beyond). When I am a very old lady I am going to let them go and live in a sumac grove. Jane
Not in your rocking chair surrounded by tree peonies, leaving the friendly neighbours to grow the sumac ?
