Japanese pieris is an ornamental shrub that boasts year-round beauty and interest. Native to Asia, Japanese pieris is an early bloomer, erupting in delicate flowers for about two weeks during the late winter and early spring. The white or pale pink blooms resemble those of lily-of-the-valley, without the strong, notable fragrance.
Best planted in the spring or fall, Japanese pieris grows slowly and will take its time establishing itself in your landscape. Because of the habit, the plant makes a good choice for foundations and shrub borders—you don't run the risk of damaging nearby structures or losing control of the plant's growth or spread.
|Botanical Name||Pieris japonica|
|Common Name||Japanese pieris, Japanese andromeda, lily-of-the-valley shrub|
|Plant Type||Evergreen shrub|
|Mature Size||9–12 ft. tall, 6–8 ft. wide|
|Sun Exposure||Full sun, partial shade|
|Soil Type||Moist but well-drained|
|Bloom Time||Late winter, early spring|
|Flower Color||White, pink|
|Hardiness Zones||5–8 (USDA)|
|Toxicity||Toxic to dogs and cats|
Japanese Pieris Care
Japanese pieris is well-loved for its ease of care and year-round interest. As long as you give the shrub the right amount of light and water, it will thrive in most locations. Japanese pieris plants like to be partially shielded for especially rough weather conditions like intense wind or rain. Once the shrub is established, you shouldn't have to do much pruning—the way it grows naturally is most attractive, and the most you'll need to do is remove spent flowers after blooming for a cleaner look.
Japanese pieris plants prefer to grow under full sunlight, getting at least six to eight hours a day. In warmer climates, you can get away with planing your Japanese pieris in a partial shade location that shields it from the harsher afternoon light.
Plant your Japanese pieris in soil that is rich in organic matter, moist, and well-draining. The plant does not do well in soggy blends and can be susceptible to root rot if its soil retains too much moisture. Additionally, Japanese pieris plants love soil with a mildly acidic pH level; before planting, check the soil pH—if you find you need to increase its acidity, you can add a specialized fertilizer for azaleas, camellias, and rhododendron, which contains sulfur to increase the pH level.
Japanese pieris plants need regular deep watering about once a week, either from natural rainfall or manual methods. Generally, you should aim to keep the soil consistently moist down to about 3 inches deep. A top layer of pine needle mulch, about 2 to 3 inches thick, can also help to retain moisture.
Temperature and Humidity
As long as it's planted in the proper USDA hardiness zone, Japaenese pieris does not have any special temperature requirements. Do your best to protect the plant from cold or especially harsh winds, which can result in leaf browning or die-back.
Add a fertilizer formulated for azaleas, camellias, and rhododendron in mid-February and mid-May, following the package instructions for the amount.
Japanese Pieris Varieties
There are numerous cultivars of Japanese pieris that vary in hardiness, size, flower color, and bloom time, including compact cultivars that are suitable for containers. Some of the most popular varietals include:
- Pieris japonica 'Mountain Fire': This varietal is one of the most popular cultivars, thanks to its vibrant red-orange foliage. It has a compact growth habit and will grow to be about 4 feet tall and 3 feet wide over the span of 10 years.
- Pieris japonica var. yakushimensis 'Cavatine': This dwarf cultivar grows to only about 2 feet tall and wide. It has an abundance of creamy-white, bell-shaped blossoms and blooms later than most, around late April or early May.
- Pieris japonica 'Valley Rose': This varietal is a compact, rounded cultivar with light pink flowers that bloom in late winter or early spring. It grows to between 3 and 5 feet tall and wide and is hardy in USDA zones six through eight.
- Pieris japonica ‘Dorothy Wyckoff’: This compact varietal grows vigorously, reaching about 5 feet tall and wide at maturity. It boasts deep red buds, pale pink flowers and is especially well-suited to container growing.
Common Pests and Diseases
Japanese pieris can be affected by a number of fungal diseases—including leaf spot and phytophthora root rot—which can spread especially easily in humid weather. Because of this, proper spacing—whether you plant more than one pieris or other shrubs nearby—is crucial for good air circulation and plant health. Allow about 6 to 7 feet between shrubs, and keep in mind their mature size.
Common pest issues for Japanese pieris plants include are nematodes, mites, and lace bugs, which suck on the leaves (also known as leaf stippling), making them yellow and unsightly. Treat any signs of pest issues using a horticultural oil, such as neem oil.