Peonies normally do not bloom within the first year of being planted and, if planted in the spring, they can take two years to bloom. Established peony plants suffer bloom failure for a number of reasons, including extremely hot or dry weather.
An unusually late frost can kill buds before they open.
Tuber size affects how quickly peonies will bloom after they are planted. Small tubers or tubers with less than three eyes will not usually bloom within the first three to five years after planting. Make sure each peony tuber has three or four eyes on the top.
Ants do not have anything to do with peony buds opening.
Planting depth and location affect how well peonies bloom. Tubers should be planted with the tops of the tubers no deeper than 2 inches below the soil surface and the planting location should have good drainage capabilities. Tubers that are planted in wet locations will struggle to grow and bloom.
Peony buds can be killed by thrips.
Dividing and transplanting peonies will affect blooming. Peonies are sensitive to being dug up, divided and moved to another location, even within the same yard. Newly transplanted peonies may fail to produce blooms for two to three years. Transplanting them in the spring will cause a longer bloom delay than fall transplanting.
Avoid applying fertilizer directly on the base of peony plants.
Peonies will not thrive and bloom in nutrient-poor soil. They should not be planted in crowded garden areas or near shrubs and trees where they have to compete for nutrients. Too much fertilizer can also be a problem, resulting in reduced blooming and weak flower stems. Peonies should be given low-nitrogen fertilizer, such as a 5-10-10 balance, in the spring after the plant has grown to 2 to 3 inches tall.