Peonies have large, sometimes fragrant blossoms. The plant grows to heights of 2 to 4 feet. Peonies are perennial plants, which means they come back each year. The blossoms are attractive in cut flower arrangements. They are rarely bothered with pests, with the exception of scales. Scales are controlled by removing affected plant material during the autumn and using a pesticide the next May or June.
Early autumn is the best time to plant, divide or transplant peonies. It is also acceptable to do this in the early spring months, as soon as the ground is workable. Each plant requires a space approximately 3 feet in diameter. The hole needs to be large enough to accommodate the roots and some additional organic matter. Place it in the soil so that the small, red-colored buds are 1 or 2 inches below the soil surface. Water it well.
Provide a well-drained location that receives full sunlight for the peony to thrive. It prefers a pH of 6.5 to 7.5, according to the University of Rhode Island website. The plant is tolerant of many soil conditions but must have plenty of organic matter to grow well.
Problems with blooming may result from an assortment of reasons: positioning the peony in the hole too deeply, using immature plants, locating it too near other plants or root systems and late frosts. Other reasons include too much nitrogen, not enough sunlight, overcrowding and a potassium or phosphorus deficiency.
Botrytis blight and leaf blotch are two fungal problems that affect peonies at times. Damp, humid weather exacerbates the problem. Quick removal of affected leaves and flowers helps control fungal diseases. Avoid watering the plant overhead as this can create the right conditions for the fungus.
Blooms appear for approximately one week in the late spring or early summer. Gardeners can extend the blooming season up to six weeks by selecting varieties that bloom early, midseason and late in the season. The large blossoms come in many colors except blue.