Japanese barberry

Japanese barberry: how do you recognise it?

Habit

Dense, rounded shrub of 1–2 m with many thin, thorny twigs.

Leaf

Alternate, in small clusters, small (1–3 cm), untoothed, green or red; fine autumn colour.

Bark

Grooved twigs with spines: single on Japanese barberry, three-pronged on common barberry. The wood and roots are bright yellow.

Flower

Small yellow flowers in April–May.

Fruit

Glossy red, elongated berries that stay on the shrub for a long time.

Difference from gooseberry

Gooseberry has lobed leaves and hairy berries.

Flowering: April–May · Pruning: June–September

Identify by feature: Yellow flowers in spring · Red berries · Thorns or prickles

Looks like it, but isn’t

• Gooseberry Ribes uva-crispa: lobed leaves and hairy berries. Difference from gooseberry

Why grow it?

• A low, thorny hedge that needs little maintenance and tolerates drought.
• Green-, red- or yellow-leaved varieties with vivid autumn colour.
• Flowers for insects in spring.

Japanese barberry: where does it grow best?

• Sun to partial shade; red-leaved varieties colour best in the sun.
• Any well-drained soil, even dry; it dislikes waterlogged soil.
• Allow 1–2 m height and 1.5 m width; there are also dwarf varieties.
• Don’t plant it near woodland, a hedgerow or a nature area: seedlings can run wild there.

Light

Sun or partial shade

Legal basis

Any garden soil

Moisture

Dry

Size

2 m tall, 1.5 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• English lavender: Purple beside red leaves, in the same dry, sunny spot.
• Spiraea: An easy, low flowering shrub for the same border.
• Burnet rose: A native, low thorny shrub for the same dry spot, and a good alternative.

Good and bad companions

Goes well with

• Suits the woodland edge or the light shade of: ginkgo, box elder, ash, honey locust, field maple, silver maple

Japanese barberry: when and how to plant it?

1. Plant from November to March, or from a pot outside periods of frost and drought.
2. For a low hedge: 3–4 plants per metre.
3. Plant at the same depth as before and firm the soil; wear thick gloves.
4. Water after planting and during dry spells in the first year.

Care

Watering

Only in dry spells during the first year; after that it tolerates drought well.

Feeding

Not needed.

Seedlings

Pull out seedlings in the garden and the surrounding area straight away, roots and all.

Tidying up

Carefully clear up clipped twigs: they keep pricking in the lawn for a long time.

Tip: Spread a sheet under the hedge when trimming: you collect all the thorny twigs in one go, and they won’t prick hands and feet later.

Japanese barberry: when to prune it?

Pruning months: June–September.

When: After flowering and, if needed, again in late August.

How:

• Trim a hedge into shape after flowering, and again in late summer if needed.
• A freely growing shrub: now and then, saw an old stem off at the base; this keeps it young and dense.
• Trimming after flowering removes a large share of the young berries at the same time: birds then spread less seed.

Caution: Wear thick gloves; clipped twigs keep pricking in the lawn for a long time.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In summer, take 10 cm cuttings of semi-ripe wood and put them under glass or plastic. Don’t propagate it for spots near woodland or nature areas.

Japanese barberry: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Fully hardy.
• After the autumn colour, the leaves drop; the red berries often hang on well into winter.

Diseases and pests

• Running wild: Birds carry the berries to woodland edges, where dense, thorny thickets crowd out native plants. Pull up seedlings and dig out unwanted shrubs with their roots; just cutting them down doesn’t help, as they regrow.
• Berberis sawfly: Pale larvae with black spots and yellow patches strip the leaves in summer. Pick them off; the shrub usually leafs out again.
• Wilt: Branches or whole sections suddenly die (verticillium wilt). Cut them back well into healthy wood and don’t plant a new barberry in that spot.

Through the year

• April: Small yellow flowers for bees and bumblebees.
• June: Trim the hedge after flowering.
• July: Finish pruning; watch for sawflies.
• August: If needed, a second trim in late August.
• September: Last pruning; pull up seedlings in the surrounding area.
• October: Autumn colour and red berries.
• November: Dig out unwanted shrubs.

What can you use it for?

Garden and landscape

Low, thorny hedge in green, red or yellow.

For wildlife

Flowers for insects, berries for birds.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Birds

Berries, seeds or insects as food, or a place to nest.

Did you know?

• The wood and roots are bright yellow.
• In a few US states it may no longer be sold, because it overruns forests there.
• The species name honours the Swedish botanist Carl Peter Thunberg, who worked in Japan for the Dutch East India Company in the 18th century and described its flora.
• Common barberry spreads black stem rust to cereals and was therefore eradicated in many places. Japanese barberry hardly does, and was promoted in the US as a replacement.