As per the flower type, peonies are named single, double, semi-double, full double, etc. While the herbaceous peonies die in winter and regrow in spring, the tree types lose leaves in winter. The intersectional types die in winter and regrow in spring. These plants are not messy but little care can work wonders.
In case of water retention, root rot may develop in peonies. The soil must be mixed with compost. This is unavoidable, if the soil is mainly composed of clay. In case, the soil is alkaline, it will be better to use rhododendron (or azalea) soil mixture, instead of compost. You may also add a small amount of high phosphorous fertilizer to the soil.
Planting: If you are using herbaceous peony roots with eyes (buds), ensure the eyes are carefully handled. Even their placement inside the soil, is important. In regions with cold climates, the eyes must be five cm below the surface, and in warm climates, the depth should be 2.5 cm from the soil surface.
If you think that you have planted them deep, remove some soil from the surface. If you plant them very deep, the plants will fail to bloom. Otherwise too, peonies may not bloom during the first year of planting. According to experts, it will be better to remove buds that develop during that year, because this results in root growth.
✦ Transplanting should be done in plants more than 15 years old. Dig out the root clump and clean the soil. Remove the foliage, and cut into root parts. Each root part must have at least four to five eyes. If there are any soft or damaged parts, apply some fungicide on them, before planting these root sections.