Peonies should be planted in a location that receives at least six hours of sun each day. The soil should be cultivated to a depth of 12 to 14 inches and amended with composted manure to provide nourishment and light soil in which roots may easily spread and develop. Plant new tubers with the eyes up, and the roots growing down. The top of the eyes should be no more than two inches below the level of the soil. Planting the tubers too deep, and lack of enough sunlight are the two main reasons peonies may not bloom and thrive. Feed peonies in the fall and again in the spring when growth begins. Use a granular fertilizer relatively low in nitrogen, like a balanced 10-10-10- or 5-10-10 formula, to encourage root and flower growth.