Pieris japonica, also known as lily-of-the-valley shrub, is an evergreen shrub valued for its pendulous flower clusters, ease of cultivation and attractive foliage. The plant blooms from summer through winter, producing numerous fragrant flowers in shades of pink and white. Pieris japonica typically reaches 10 feet in height, though a smaller size can easily be maintained with annual pruning. Native to Japan, Pieris japonica thrives in most temperate regions of the world and makes an excellent hedge, perennial border or stand-alone specimen.
Plant Pieris japonica during early fall in a location that receives light to partial shade throughout the day and consists of rich, moist, well-drained soil. Space Pieris japonica plants at least 6 to 10 feet apart to allow adequate room for growth.
Spread a 1- to 3-inch layer of mulch over the soil surrounding the shrub to provide insulation, prevent weeds and improve moisture conservation. Begin the mulch at least 3 inches from the plant's base to allow air circulation and prevent rotting.
Water Pieris japonica once per week during spring, summer and fall to prevent the soil from drying out completely. Reduce watering frequency to once every two to three weeks during winter, when the plant's active growth has ceased. Soak the soil to a dept of at least 6 inches at each watering.
Fertilize once every year during early spring using a 14-7-7 NPK fertilizer. Apply at the rate recommended by the manufacturer's instructions. Water lightly before and after feeding, soaking the soil to a depth of at least 2 inches, to prevent root injury and release the nutrients into the soil.
Prune Pieris japonica immediately after blooming ends to improve the plant's aesthetic appeal and overall health. Trim back any excessively long growth and remove any damaged or diseased limbs as necessary using hedge clippers.