Peonies are one of the early bloomers in many Southern gardens. Usually very hardy, even peony plants have a few requirements to ensure that they will produce beautiful flowers for many years to come.
Peonies need to be planted with their eyes no more than 1 to 3 inches below the surface of the soil. If they are planted too deeply, the peony will have delayed blooms, or no blooms at all.
When a peony has been in one spot for several years, the soil can become depleted of nutrients. This can eventually cause the peony to stop blooming and become yellow and spindly.
Peonies require at least six hours of daily full sunlight to produce blooms. Avoid planting peonies near plants or shrubs that will grow tall and eventually block the sunlight.
Peonies will fail to boom, but will have an abundance of foliage, if they are fed with a fertilizer mix that contains too much nitrogen. They prefer a balanced fertilizer applied twice a year.
Disease, such as Phytophthora blight, or Botrytis blight, can infect peonies and cause them not to bloom. Proper sanitation, and using fungicides as needed, can often prevent these problems.
A late freeze can damage the peony flower buds and they will not bloom. Another weather-related reason for a lack of blooms is dry weather, which will result in fewer flowers the next year.