Though sometimes advertised in the prairie provinces, they are generally not hardy and are not recommended. Peonies are best planted, transplanted, and divided in the fall. The planting hole should be large enough so that the peony is not crowded. Heavy clay soils or light sandy soils can be improved by the addition of an equal amount of peat moss, thoroughly mixed with the existing soil. Deeper planting will delay or inhibit flowering, while shallower planting might make the bud more vulnerable to frost or mechanical injury.
Deep planting is the most common reason for failure of peonies to bloom.
But keep in mind that it is normal for some varieties to take up to 2 or 3 years to bloom after planting or transplanting. When dividing an older peony, wait until mid-September when the foliage has begun to yellow. Cut and remove the stems at ground level and then lift the entire clump. Allow it to sit in the sun for a few hours before dividing. Shake or wash off the soil and then, using a sharp spade or knife, divide the old crown so that each new division contains 3-5 buds or eyes.