How to Plant, Grow, and Care For Lily-of-the-Valley Shrubs

Pieris japonica is a woody shrub that brims with all-season appeal. It develops showy, pendulous beads of flower buds in late summer that persist through winter. The buds open in late winter and early spring for a sweet welcome to the season.

Pieris is unique with its suspended blooms and is commonly called lily-of-the-valley bush for its resemblance to the spring-flowering perennials (Convallaria majalis). The little bell blooms carry a delicate fragrance and are a bumblebee favorite during the early season. Rosette leaves and burgundy new growth make it a versatile multi-season shrub.

What Are Lily-of-the-Valley Shrubs?

Pieris (also called Japanese andromeda) has pendulous white flowers that droop gracefully from whorled, leafy stems. In addition to the winter buds and blooms is striking new growth. Fresh leaves and stems emerge bronze and red and mature to deep, glossy green. The narrow, pointed leaves appear in bushy rosettes along the stems.

Feature lily-of-the-valley shrub in a mixed evergreen hedge or foundation planting for texture, floral interest, and dynamic foliage. Group them for impact, or showcase them in a large container. Numerous cultivars bring a range of sizes, foliar interest, and blooms in white, rose, and pink. They pair beautifully with other acid-loving plants like azaleas, rhododendrons, and camellias.

Characteristics

Pieris has a dense, upright habit filled with leafy stems. New growth is bronzey-red, with established foliage in deep, olive green. The narrow, glossy, evergreen leaves reach three and a half inches long and whorl around stems. Up to three and a half inches long, they emerge bronzey red and mature to dark olive. 

The big ornamental draw is the drooping flower clusters, or racemes, that reach up to six inches long. The beads bring delicate beauty from late summer until bursting open in late winter and into early spring.

Dry, small fruit capsules emerge along the racemes after flowering. They mature in late summer and persist through winter.

P. japonica can be a bit finicky in finding its right conditions to maintain disease resistance, but it is relatively low maintenance when it does. The shrub is deer resistant due to high toxicity – poisonous to humans and animals if ingested. There are over 40 cultivars to delight with multi-season interest across garden scales.

Native Area

P. japonica originates in southern to central Japan, Taiwan, and southeast China. Its native habitat is woody mountain thickets, where it grows at elevations with cool, mild climates.

The genus is in the heath family (Ericaceae) along with rhododendrons, mountain laurel, blueberries, cranberries, and wintergreen.

Planting

Lily-of-the-valley bush has a slow growth rate, reaching its mature average of 6 to 10 feet tall by 6 to 8 feet wide over a decade. A minimum spacing of five feet between specimens works well, and more closely for hedging (four feet apart or so).

Situate the broadleaf evergreen out of winter winds for added hardiness protection.

Transplanting

With shallow roots, plant the crown a little high to prevent settling. Situate it two to three inches higher than the surrounding soil. If the crown falls below the soil line, stems will struggle to develop. Keep the soil/crown level consistent from the nursery container to the in-ground spot.

Spring and fall are the best times for planting with their moderate temperatures and ample moisture. The extreme heat of summer in southern regions is stressful for new additions; make sure to provide regular moisture.

How to Grow

Pieris performs best in conditions that mirror those of rhododendrons, azaleas, and camellias. In areas where they contend with hot summers and cold winters, they may show decreased hardiness. In their optimal growing conditions, they need little ongoing maintenance.

Light

Japanese andromeda grows in full sun to shade, but performs best in partial shade. In hot, southern climates, provide afternoon sun protection. Afternoon shade prevents scorch and weakness from heat. Morning sun exposure is ideal, with dappled light the remainder of the day.

P. japonica tolerates deep shade, but will flower less. Foliage is also not as colorful in heavy shade.

Water

The shallow-rooted woodies need regular water until established. During their first growing season, they need regular, deep-watering sessions to establish sturdy roots. Reduce frequency in successional seasons, offering supplemental irrigation during gaps in rainfall. Water at about one inch per week or when the top three inches of soil are dry.

While they appreciate consistent moisture, they won’t thrive in constantly wet conditions. Overly wet soils lead to fungal problems like root rot.

Soil

Pieris thrives in acidic, organically rich, well-drained soils suited to companion plants of azalea and camellia. The ideal soil pH is 5.0 to 6.0.

Alkaline soils stress the acid-loving shrubs. If yellowing leaves show green venation, it may be a sign of chlorosis and a high pH. Add iron chelate to the soil and amend with completely broken-down plant material to lower alkalinity. A soil test helps determine if other amendments, like aluminum sulfate, are beneficial.

If native soils are lean, sandy, or clay-based, amend with leaf mold or compost worked into the soil at planting to improve organic richness and increase aeration. Make sure to incorporate it with the native soil backfill.

Temperature and Humidity

Lily-of-the-Valley shrub is hardy in zones 4 through 8 and appreciates shelter from drying winds, especially in winter. A two to three-inch mulch layer provides insulation in winter and cooling moisture in summer.

Pieris grows in zones with heat and humidity, with shade protection against summer heat. It may develop fungal issues like leaf spot if humid conditions create lasting damp conditions.

Fertilizing

In rich, fertile soils, P. japonica doesn’t need fertilizer every year. To boost nutrition in lean soils, fertilize in the spring with a formula for acid-loving plants like azaleas, rhododendrons, and camellias, or a 10-10-10 with minerals and micronutrients. Minerals like magnesium, calcium, and sulfur, and micros like manganese and iron are important to camellia nutrition. Check the formula to look for minor elements. 

Maintenance

Do any necessary pruning shortly after blooming so new buds can set for the following season. Pieris tolerates hand-pruning to retain shape, manage size, and increase airflow between branches. Buds set on old wood, so pruning anytime other than right after flowering risks losing the next season of blooms. 

Scout for and remove any dead, diseased, or crossing branches. Hand cutting with clean, sharp loppers or pruners is best; avoid using hedge trimmers to shape.

Mulch with straw, bark chips, or leaf litter for insulation, temperature regulation, and moisture retention. Keep the layer away from the stems to minimize disease.

Propagation

Pieris are slow to propagate but do so primarily through cuttings and seed. Cuttings need to stay consistently moist and warm as they slowly root. They’ll be ready for the garden in a few months.

Cuttings

Take stem cuttings in early summer after the woody plant finishes blooming. To propagate via cuttings:

• Cut a four- to six-inch piece of healthy stem with young tip leaves and no flowers.. 
• Remove the foliage from the bottom ⅔ of the cutting (keeping at least two leaves intact). Keep cuttings moist until ready to pot.
• Optional: moisten the cutting and generously coat the lower stem with rooting hormone. Tap off any excess rooting powder.
• Plant the cutting in at least two inches of moist, well-draining potting mix in a tray or four-inch pot.
• Place the pot or tray in a bright, warm location (68-75°F or 20-24°C), avoiding direct sunlight.
• Water/mist to keep the soil evenly moist.
• When the cutting resists a gentle tug after about 8 to 10 weeks, roots are in place and ready to be repotted.
• Keep the cuttings in four-inch pots for a few more weeks,  and move them outside in mild conditions. New plants will be tender.

Seeds

Collect dry seeds in the fall for spring sowing, storing them in a cool, dry spot over the winter. Before sowing, soak them overnight to soften the outer seed coat. Fill four-inch pots with potting mix and moisten it thoroughly. Sow one seed per pot, pressing it lightly onto the soil surface. Cover only lightly with the potting mix, allowing light exposure for germination. Mist the seeds, and place a piece of plastic wrap over the pots to create a humid, mini-greenhouse environment to prevent drying.

Place the pots in bright, indirect light and mist daily to maintain even moisture. Seeds germinate in about one month. Remove the plastic wrap as sprouts emerge. When the seedlings reach three inches tall with a few sets of leaves, they’re ready for hardening off and moving to the garden.

Popular Varieties

From compact to towering, leafy forms with shades of fiery red new growth and rosy blooms, pieris cultivars bring high interest. 

‘Mountain Fire’

	botanical name Pieris japonica ‘Mountain Fire’
	height 6-10’

‘Mountain Fire’ is a tall favorite with showstopping bright red new growth. The upright stems tipped in crimson provide an all-over glow. 

White blossoms are prolific for high contrast against the newly emerging red leaves. The fiery red and the cooling white are a spectacle in spring.

‘Cavatine’

	botanical name Pieris japonica ‘Cavatine’
	height 4′

‘Cavatine’ is a stunning small cultivar with loads of buds. Very slow-growing, it reaches its mature two-foot height in a decade of growth.

Snow white flowers appear in early spring for a graceful display and contrast to the deep green leaves. Grow ‘Cavatine’ in a pot or tuck it into small garden spaces for a year-round presence.

‘Interstella®’

	botanical name Pieris japonica ‘FARROWPJRF’
	height 3-4’

‘Interstella®’ mixes up the scene with a profusion of ruby rose blossoms in large clusters that drape over dark foliage.  New growth emerges red before transitioning to olive.

‘Interstella®’ is one of the earliest to bloom and among the most shade-tolerant, flowering even in low light. It boasts a long bloom time of two months or more, followed by glowing foliage.

Common Problems

Lace bugs, scale, spider mites, and nematodes sometimes affect P. japonica. Potential diseases include Phytophthora blight.

Pests

The best way to control insects is to spot them early. You’ll likely see the insects themselves or notice their systemic indicators.

Sap Suckers

Common sap-sucking pests congregate on the undersides of leaves to feed with piercing mouthparts. They may cause yellow stippling on the surface, yellow blotches, wilting, and leaf drop. Lace bugs favor Pieris and other deciduous species. They likely won’t impact the overall health of mature specimens, but can do damage through premature leaf drop in young transplants over consecutive seasons.

Scale are common sap-sucking insects that look like gray dots on stems and leaves. Branches may die back in heavy infestations. Remove affected leaves (and branches, if severe).

Spider mites present with webbing and light yellowing of leaf surfaces. They occur in dry and dusty conditions, particularly in shrubs experiencing drought stress. Predatory insects like ladybugs and predatory mites help control populations.

In pest outbreaks, spray the plant with a strong stream of water to deter and knock insects off the stems. A horticultural soap or oil is effective if infestation occurs, but be sure to follow label directions, as these affect beneficial insects as well. 

Nematodes

Foliar nematodes are slender roundworms that are difficult to see with the naked eye. They damage upper growth and spread quite quickly. The first sign is yellow-brown lesions on the leaves between veins. These spots start on the lowest leaves and work their way up. They’ll eventually cover the entire leaf, which dries and drops prematurely.

Nematodes climb/ swim up stems in a water channel after rain or irrigation. They enter the leaves for feeding, and their damage may kill the andromeda.

Nematodes overwinter in the soil and debris from affected specimens. Good garden cleanup is a best practice. Mulching prevents water from splashing onto stems and leaves, lessening access for nematodes.

Because nematodes spread readily and dwell for years in debris, remove and discard severely infected plants and the surrounding surface soil. Dispose of them away from the garden and compost pile.

Insecticidal soap may help as a treatment. In severe cases, spray surrounding plants, too, to catch nematodes before they enter the tissues of otherwise healthy selections.

Diseases

As with pests, the best disease control is prevention through cultural conditions. Fungal root rot can occur in overwatered situations. Root rot causes plants to decline due to an inability to absorb water and nutrients. The pathogen Phytophthora impacts feeder roots, preventing them from uptaking water and nutrients. Leaves appear drought-stressed, turn yellow, and wilt.

Look for rot slightly below the soil level. If rot is the problem, the stems will be yellow, and the roots will be brown and mushy rather than healthy white.

If caught early and with only minor damage, the shrub can recover. Reduce irrigation frequencies to allow oversaturated soils time to drain. Keep soil evenly moist but not soggy. 

Proper cultural management, especially not overwatering, is the best control. Water deeply and increase the length of time between sessions if needed. 

Frequently Asked Questions