Beside this, should I prune tree peony?
Tree peonies require minimal pruning.Justremove flowered shoots, cutting them off just above the newgrowthon the stem in summer; or in the autumn after the seedsarecollected if this is desired. Remove any dead shoots inlatewinter, cutting back to a healthy bud. Stems may become leggyovermany years.
Subsequently, question is, when should you prune a tree peony?
Tree peonies generally respond quite welltopruning, which is best under taken in late winter orearlyspring, just as the buds begin to swell - so now istheideal time!
limit mulch to no more than 2 inches and keepitback away from the stems. Tree peonies like soilthat'sneutral to slightly alkaline on the pH scale (around 7or atad above), and they benefit from a few doses of granular,balancedfertilizer in spring and summer.