Ornamental juniper

Ornamental juniper: how do you recognise it?

Habit

Ornamental conifer of 0.5–5 m: creeping, spreading or columnar.

Leaf

Young shoots with prickly needles, older ones with scale-like leaves; often blue-grey with a resinous scent.

Bark

Reddish-brown, peeling in strips.

Fruit

Small, blue, berry-like cones with a waxy bloom.

Difference from common juniper

The native common juniper has only prickly needles, in threes.

Difference from thuja

Thuja has only flat sprays of scale leaves.

Pruning: May–June and August–September

Identify by feature: Prickly needles · Scales instead of needles

Looks like it, but isn’t

• Common juniper Juniperus communis: only prickly needles in threes. Difference from common juniper
• Thuja Thuja: only flat sprays of scale leaves. Difference from thuja

Why grow it?

• Evergreen and in every shape: creeping, spreading or columnar.
• Tolerates drought, wind and poor soil; ideal for a sunny bank or gravel garden.
• Blue-grey, green or yellow foliage gives colour and structure all year round.
• Creeping forms suppress weeds and need almost no maintenance.

Ornamental juniper: where does it grow best?

• Full sun; in shade it becomes thin and bare inside.
• Any free-draining soil, even poor and dry; no wet feet.
• Allow 1–3 m width, depending on the variety: read the label carefully.
• Not near pear trees: pear rust spores are carried a few hundred metres on the wind.

Light

Full sun

Legal basis

Any garden soil

Moisture

Dry

Size

5 m tall, 3 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• Heather: Purple late-summer flowers among the grey-green foliage, for a sunny, acid spot.
• English lavender: Fragrant purple summer flowers for the same sunny, dry spot.
• Common rock-rose: A low, flowering dwarf shrub for the edge of a bank or gravel garden.

Good and bad companions

Best kept away from

• Gets pear rust from this plant: pear, wild pear

Ornamental juniper: when and how to plant it?

1. Plant from a pot in spring (April–May) or early autumn (September–October).
2. Dig a generous planting hole and mix heavy soil with some coarse sand or gravel for better drainage.
3. Set the root ball at the same depth as in the pot and firm the soil.
4. Water well after planting, and in dry spells during the first year.

Care

Watering

In dry spells during the first year; after that it copes almost anywhere without.

Feeding

Rarely needed; on very poor soil, a little compost in spring.

Combing out

Dead, brown needles inside the shrub are normal: shake or comb them out to keep the shrub airy.

Pear rust

In April–May, look for swollen shoots with orange, jelly-like outgrowths and cut them off.

Tip: Choose the variety by its final size: a creeping juniper often grows 2–3 m wide, even if it looks small in its pot.

Ornamental juniper: when to prune it?

Pruning months: May–June and August–September.

When: In May–June or in late summer.

How:

• Only cut into the green part; a juniper won’t regrow from old, bare wood.
• Remove overlong or awkward branches from inside the shrub, so it keeps a natural shape.
• Keep a creeping form in check by cutting the longest branches away underneath the others.

Caution: Don’t shear a juniper like a hedge: anything that goes bare won’t fill in again.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In August–September, pull off a side shoot with a heel and insert it in sandy cutting compost, kept cool and moist; it roots slowly.

Layering

Creeping forms often root by themselves where a branch touches the ground: cut that piece free in spring and plant it elsewhere.

Ornamental juniper: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Fully hardy; some varieties turn purple or bronze in winter.
• Heavy snow can splay columnar forms: shake the snow off or tie the branches loosely together with soft twine.

Diseases and pests

• Pear rust: Orange, jelly-like outgrowths on swollen shoots in spring; later, orange spots on pear leaves. Cut off affected shoots and don’t plant near pear trees.
• Root rot: On wet soil the shrub turns greyish-brown and dies. Plant in a free-draining spot.
• Spider mites: In hot, dry summers the foliage turns grey or brown, with fine webbing. Hose the shrub down and water in dry spells.
• Brown patches: On creeping forms often caused by dog urine or a layer of wet leaves. Cut out dead parts; they won’t grow back.

Through the year

• April: Planting; cut off shoots swollen by pear rust.
• May: Prune within the green part.
• June: Finish pruning; watch for spider mites in dry weather.
• July: Water in long dry spells, especially young plants.
• August: Late-summer pruning; take cuttings.
• September: Last month for pruning; planting possible again.
• December: Shake snow off columnar forms.

What can you use it for?

Garden and landscape

Ground cover or low ornamental conifer for sunny, dry spots.

Caution: Alternate host of pear rust: don’t plant it near pear trees.

Did you know?

• Many ornamental junipers are an alternate host of pear rust: the fungus that causes orange spots on pear leaves.
• The ‘berries’ are actually small cones with fused, fleshy scales.
• Many ornamental junipers carry juvenile foliage (needles) and adult foliage (scales) at the same time; some varieties keep their juvenile form all their lives.
• The Pfitzer juniper is a cross between Chinese juniper and savin, named after the German nurseryman Wilhelm Pfitzer of Stuttgart.
• Chinese juniper is one of the classic bonsai species, and has been for centuries in Japan and China.