If you are saying it is a large
plant is it a
tree peonies? I mean one stalk and many blooms. If it is I would ask him not to dead head and allow the
seeds pods to form if the variety is one that produces good
seeds. From
seed it takes about 4 years to get a
plant mature enough to bloom. Once planted they do not like to be disturbed but they can live for up to 100 years so they are well worth the wait.
On the other hand if you mean that the clump has many stems then the best way is to take a root division. This is the best way to propagate peonies. Make sure each division has between three and five eyes on it. And again it should take anywhere from 3 to 7 years to see the first bloom. Although I did have one of mine bloom at the end of the second year.
Other than that make sure that you
plant them in a wind protected area since the blooms will shatter under windy or heavy rain conditions.
Good luck, I love my peonies. Next year will be my third year with them and I can't wait to see them bloom.