I have a beautiful tree peony in my new garden that is blooming with profusion. However, it has completely collapsed to one side. I don't know how or when this happened as I only just moved here. I would like to get it more upright but am not sure how. I've tried staking it but the stem has become too woody and rigidly bent over. If I cut the peony back, how low down can I cut? I see some lateral shoots further down the stem, but to get it upright again, I'd have to cut back to about 8 inches above ground - that's a lot lower than any of the new lateral shoots. Is it ok to do that or will I regret it? Thanks!