I recently had my roof replaced and in the process of removing the old roof, a slab of shingles came crashing down on top of my six year old peony trees. While each plant was about three foot tall, they both had become quite scraggly and couldn't bear the weight of the shingles. Needless to say, the branches broke and some snapped under the pressure.

One plant we had to cut nearly to the ground; the stem is about 8" from the ground. The other had a couple of branches survive.

My question is:

Should I trim the other plant so that they will grow back in unison? Is the tree even going to grow back?

These are the predominant plants in this flower bed that faces the street so I don't necessarily want to wait too terribly long to have them back to their previous glory.

I appreciate any advise that you care to give.

Thank you in advance for your attention.