The fern peony, Paeonia tenuifolia, is an easy to grow and maintain herbaceous perennial that grows from a thick ball of tuberous roots. The plant has fine fern-like green leaves and produces a dark red flower that blooms in late spring. Fern leaf peony plants grow to a height of 1 to 3 feet and are hardy to plant in USDA growing zones 3 through 8. The best time to plant the fern peony is early summer or in the fall season.
Select a planting location for the fern peony plant that has well-draining soil and full to partial sunlight conditions. The soil type can range from a sandy loam to a soil with small amounts of clay.
Dig a hole for the fern peony so the root ball is 1 to 2 inches below the soil surface. The fern peony will not grow if planted too deep. Place the plant into the hole and gently pack the soil around the root ball.
Water the plant generously after planting. Continue to water the fern peony throughout the growing season so the soil remains moist. Do not allow standing water around the plant.
Fertilize the fern peony every two weeks during the growing season. Apply a water-soluble, general purpose fertilizer to the soil area above the root ball.
Apply 2 to 3 inches of mulch around the plant to prevent weed growth and increase moisture retention in the soil.
Remove fern peony blooms once they have faded by cutting them from the plant. Do not cut back the foliage until the first frost in the fall season has occurred.