Paeonia japonica, more commonly known as the Japanese or Mountain Peony, is a popular garden plant. Although, not as flashy as its Paeonia lactiflora cousins, it is none-the-less appreciated for its large, beautiful and fragrant flowers. Originally from Japan, these peonies have been cultivated for thousands of years. The plant was not only raised for its flowers, but was also used in traditional herbal medicine.
The foliage consists of large, lobed or lance-shaped leaves that are deeply veined that are paired along a thin stem. The flower is white and cup-shaped with a yellowish center and can be up to 3 inches in diameter. The stamens in the center of the flower are yellow. Peony blossoms are showy and very fragrant. The flower blooms in spring and each blossom lasts for 7 to 10 days.
The plant grows relatively quickly. Plants will live for many years and do not need to be divided. Japanese peonies will grow well from hardiness zones 5 through 8. As the flowers finish, they will be replaced by seed pods that will eventually open to reveal blue seeds on red stalks.
The plant is herbaceous, or soft stemmed, and reaches about 18 inches in height. The leaves spread between one and two feet from the stem. Each stem of the plant puts out will bear one flower. The plant is relatively compact. It is especially good for woodland settings.
The plant prefers partial shade. The soil should be fertile and rich in humus, with medium moisture and good drainage. The foliage should be cut to the ground after the first frost. Remove dead blossoms to encourage continued blooming.
Peony japonica is relatively trouble-free plant with few pests. Occasionally Botrytis and Phytophthora blight can affect the plant adversely. Ants like peony plants but cause no harm. If the plant is not blooming, consider reducing the shade in the area.