Chinese tree peony blossom over many years without a break, from a seedling aged 4-5 years to senescent plants aged over hundred years. In a normal year it takes 50-60 days from breaking of bud dormancy to blossoming. This period varies between different cultivators. Those blossoming early or with simpler flower forms take a shorter period, but late flower-in cultivars or those with higher rank flower forms take longer.

　　Chinese herbaceous peony blossom annually. The flowers blossom on the top of the stems or in leaf axil near the top.

Ecological Habits of Tree Peony

　　The entire ancestral is Chinese tree peonies, namely the entire group of wild species tree peonies, is categorized as typical Temperate Zone woody plants. Their distribution is concentrated on the southwestern mountains and the central northern Loess Plateau and hills forming a narrow zone of distribution. Although the southwestern area is located within warm temperate and subtropical zones, peonies there all grow above 2500 meters height above sea level. Elsewhere they have long been established in a temperate environment. In both areas therefore peonies have adapted to commonly occurring ecological habitats. They tend to grow better in mild and pleasant cool climates and they have a certain of cold. They flourish in dry and high places but are less successful in torridity, damp conditions. They need sunny days and yet tolerate half shade well. The cultivated varieties of Chinese peonies also show wide ecological adaptability. The distributions of the ancestral wild species are generally concentrated in relatively restricted areas, often adjacent to and even overlapping one another. Nevertheless, the difference between species origins, elevations of individual locations, and specific environments and conditions have helped to form various cultivar groups that are able to their own ecological environments. Thus cultivar groups have developed their particular ecological predilections. The comparison and contrast of the main meteorological elements in the principal distribution areas of each ancestral species and the cultivated of each cultivar group confirms this observation.

　　The leading elements affecting the normal growth and development of Chinese peonies are temperature and moisture, especially humidity. The various species and cultivator groups generally react adversely to what is for them an unsuitable environment, and growth is hindered. For example, when cultivars of the Southwest cultivator group are grown in the Central Plains area in China, normal development cannot be relied on and unsuccessful production of flower buds due to summer heat and dry air often leads to a lack of flowers. Exceptionally, some cultivars can adapt and bloom normally. Most cultivator groups of Chinese Peonies, however, are very adaptable and tolerant of strong sunshine and different soil conditions. Most varieties benefit from moderate sunshine and at the same time is tolerant of half shade. When in bloom, lateral shading is beneficial and prolongs flowering. Shading is especially necessary for the cultivars less tolerant of sunshine. For cultivation of the Southwest cultivator group in northern areas in China, shading from the midday sun is appropriate, especially in summer.

　　All the cultivator groups have long fleshy roots. It is the most suitable that they grow in the porous, fertile and deep soil on dry high terrain. Tree peony can grow well in soil that is generally not compressed and waterlogged, and a sandy soil is preferable to a sticky soil. The ideal pH (value) is neutral or slightly alkaline or sourish.

Ecological Habits of Herbaceous Peony

　　Herbaceous peony (Shaoyao) is a perennial herbaceous Plant. The ecological habits are generally alike to tree peony, certainly, they are better than tree peony in cold-resistance.