Photo: Wouter Hagens, Public domain · source
Shrub · Heather family (Ericaceae)
Japanese pieris
Pieris japonica · also: Pieris, Lily-of-the-valley bush
Japanese pieris is an evergreen shrub of 1–3 m from Japan and eastern China, with rosettes of glossy, leathery leaves. In March–April it is hung with sprays of white or pink bells, like lily of the valley; the buds are ready all winter. Afterwards it puts out copper to fiery red young shoots. It needs acid, humus-rich soil that stays moist but not wet, and a spot in partial shade, just like rhododendron. Be careful: all parts are poisonous, to people and animals alike.
Caution: All parts are poisonous, flowers included: they contain grayanotoxins, which cause vomiting, drooling, weakness and, in serious cases, heart rhythm problems in people and animals. Keep an eye on children, dogs and cats, and never throw prunings into a field or animal pen: goats, sheep, horses, rabbits and guinea pigs are very sensitive to them.
Light
Partial shade or shade
tolerates little sun
Moisture
Normal
no wet feet
Legal basis
Acid soil
acid
Hardiness
Throughout Belgium
no protection needed
Size
1–3 m
tall
Flowering
March–April
| Pruning months | May |
|---|---|
| Height | 1–3 m |
| Native to Belgium | No, planted |
| Good for bees, butterflies and birds | Yes, for bees |
| Poisonous to people and pets | Yes, take care with children and pets |
| Flowering | March–April |
Identify
Japanese pieris: how do you recognise it?
- Habit
- Evergreen, dense, rounded shrub of 1–3 m.
- Leaf
- In rosettes at the shoot tips, 3–8 cm, narrowly oval, finely toothed and leathery; young leaves copper to fiery red.
- Bark
- Greyish-brown, flaky.
- Flower
- Hanging sprays of small white or pink bells (like lily of the valley) in March–April; the buds are ready all winter.
- Fruit
- Small, dry capsules.
- Difference from photinia
- Photinia also has red young shoots, but larger leaves and white flower heads, and it is not fussy about soil.
- Difference from skimmia
- Skimmia has untoothed, aromatic leaves and red buds in winter.
Flowering: March–April · Pruning: May
Identify by feature: Evergreen leaves · Hanging flower clusters
Looks like it, but isn’t
- Photinia Photinia: also red young shoots, but larger leaves and white flower heads; not fussy about soil. Difference from photinia
- Japanese skimmia Skimmia japonica: untoothed, aromatic leaves and red buds in winter. Difference from Japanese skimmia
In your garden
Why grow it?
- Green all year, with fiery red young shoots in spring.
- Sprays of white or pink bells in March–April, when little else is in flower.
- The early flowers are good for queen bumblebees.
- Slow-growing and compact: suitable for a small garden or a large pot.
Japanese pieris: where does it grow best?
- Partial shade to shade, sheltered from cold winds and from early-morning sun after a frosty night.
- Acid, humus-rich soil that stays moist but not wet; on chalky soil the leaves turn yellow.
- Not under or next to a walnut: it does not tolerate juglone, the substance walnuts release.
- Allow for 1–3 m tall and about 2 m wide; in a large pot it stays smaller.
- Light
- Partial shade or shade
- Legal basis
- Acid soil
- Moisture
- Normal
- Size
- 2 m tall, 2 m wide
- Hardiness
- Throughout Belgium, no protection needed
Goes well with
- Rhododendron: Needs the same acid, humus-rich soil and partial shade.
- Camellia: Evergreen and early-flowering, for the same acid, sheltered spot.
- Japanese maple: Fine, graceful leaves and autumn colour beside the glossy green.
- Ferns: They fill the shady, acid soil at the foot of the shrub.
Good and bad companions
Goes well with
- Tolerates shade and suits planting under large trees such as: english oak, sessile oak, pin oak, turkey oak, red oak, holm oak
- Like acid soil, just like this plant: heather, rhododendron, japanese skimmia, raspberry, highbush blueberry, witch hazel, broom, gorse
Best kept away from
- Walnut releases juglone, to which this plant is sensitive: walnut
Maintenance
Japanese pieris: when and how to plant it?
- Plant in April or in September–October.
- Mix the planting soil with acid leaf compost or peat-free ericaceous compost; on chalky soil you are better off with a large pot or a raised bed of acid soil.
- Don’t plant deeper than it was in the pot: the roots are shallow.
- After planting, water generously with rainwater and cover the soil with pine needles, bark or leaf compost.
Care
- Watering
- Use rainwater in dry spells; hard tap water gradually makes the soil less acid.
- Feeding
- A little fertiliser for acid-loving plants in spring.
- Mulching
- A layer of pine needles, bark or leaf compost keeps the shallow roots cool and moist.
- In a pot
- Use ericaceous compost and a pot with a drainage hole, water with rainwater and protect the pot in severe frost.
Tip: Got chalky soil? Grow pieris in a large pot of ericaceous compost and water only with rainwater: that works much better than trying to make the garden soil acid.
Japanese pieris: when to prune it?
Pruning months: May.
When: After flowering, in May.
How:
- Little needed: cut off the faded flower sprays, just below the cluster.
- Shorten overlong or lopsided branches to just above a rosette of leaves; it will regrow from there.
Caution: Only on acid soil; water with rainwater.
Propagation
- Cuttings
- In summer or late summer, take semi-ripe cuttings of 8–10 cm and root them in a mix of sand and ericaceous compost, under glass or plastic.
- Layering
- In spring, bend a low branch to the ground, nick it lightly and cover it with acid soil; after a year it will have roots.
Japanese pieris: how does it get through the winter?
Hardy throughout Belgium: no protection needed.
- Hardy; the flower buds are ready all winter and withstand ordinary frost.
- Late frost in April damages the red young shoots and the flowers: cover the shrub with fleece when frost is forecast.
Diseases and pests
- Pieris lace bug: Leaves mottled yellowish-white on top, with small black spots and tiny bugs underneath. Cut off badly affected branches; a spot that is not too hot and dry helps.
- Yellow leaves: Yellow leaves with green veins, caused by lime in the soil or the water. Water with rainwater and feed with fertiliser for acid-loving plants.
- Vine weevil: Notches in the shape of a half-moon along the leaf edges; the grubs feed on the roots. Control the grubs in spring or late summer with nematodes.
- Frost damage: Brown young shoots after a late frost. Cut them off; the shrub will regrow.
Through the year
- March: Flowering begins: food for queen bumblebees.
- April: Flowering; protect the red young shoots from late frost; planting.
- May: Pruning: cut off faded flower sprays; nematodes against vine weevil.
- June: Mulch, and water with rainwater in dry spells.
- August: Take cuttings; nematodes against vine weevil.
- September: Planting can start again.
- December: The flower buds for spring are already in place.
Use
What can you use it for?
- Garden and landscape
- Evergreen shrub for acid soil, with red young shoots and early flowers.
- For wildlife
- The early flowers are good for queen bumblebees.
Caution: Poisonous to people and animals.
Good for wildlife
- Bumblebees
- Nectar and pollen for bumblebees, also from deep flowers and early in spring.
You and this species
Did you know?
- All parts are poisonous, to dogs and cats too. It needs acid soil, like rhododendron.
- In Japan it is called asebi, written with the characters for ‘horse’, ‘drunk’ and ‘tree’: horses that eat the leaves start to stagger.
- Pieris is named after the Pierides, the Muses of Pieria in Greek mythology.
- In Japanese the shrub is called asebi, written with characters meaning ‘horse-drunk tree’: horses that eat the leaves start to stagger.