Peonies dislike root disturbance and often don't bloom the first year after transplanting. However, a 10-year-old plant certainly should have bloomed by now. Here are some common reasons why peonies don't bloom. Not enough sunlight. Peonies need full sun in order to grow and bloom well. If your plant receives less than 6 hours of direct sunlight a day, move it to a sunnier spot. Heavy soil. Peonies like well-drained soil. If your soil is slow to drain, amend it with organic matter (such as compost) to encourage better drainage. Deep planting. If peonies are planted too deeply, the buds in the crown of the plant won't get enough light. Buds should be planted no more than an inch or two below ground level.