Transplanting peonies into clay soil--should I re-dig?
We are new homeowners and I transplanted some peonies from our backyard into our front flower bed. The peonies are a deep crimson when in bloom. One of the plants seemed to be an older plant with 7 stems and a relatively large root ball (maybe about 1 foot across). It probably could have been divided into 2 plants, but I would prefer one larger plant, so kept it as is. The other plants seemed to be more recent divisions, each with 2-3 stems each.
The soil in the back is pretty good as the former owner did most of his gardening back there. The front has about 12 inches of good amended soil on top, but is a thick, heavy gray clay underneath. Because I enlarged the bed, I amended the whole thing with cotton burr compost and a compost mix bought at a reputable nursery and made up of leaf mulch, bark mulch and probably some other things.
When I transplanted, I dug the holes twice as wide as the plants' current root systems, but only dug them as deep as necessary to keep the eyes of the plants about 3/4" below grade. (The nursery recommended planting no deeper than 3/4", but I forgot to ask how deep to dig the hole). The reason I kept the hole shallow was b/c I planted a hydrangea up front last spring and dug deeper than the root ball and amended the clay soil underneath and the hydrangea ended up sinking so much that I had to re-plant it.
I am now worried that I should have planted the peonies deeper. I think I still have time to remove the plants and re-dig the holes. What do you think? The holes are currently about 1 foot deep and, in addition to the amended soil that I back filled with, I also added about 1-2 cups of cotton burr compost and 1-2 cups of regular compost into the bottom of the hole before planting. None of the plants' roots are resting on top of the clay, but the clay layer probably begins only about 2-3 inches below the root balls.
Also, should I have divided the one larger plant before replanting? Any advice is appreciated!