Blue Star juniper

Sun

Full sun; shade makes growth looser and foliage less blue.

Water

Water regularly during establishment, allowing the surface soil to dry between soakings. Established plants tolerate dry spells but dislike persistently wet roots.

Soil

Well-drained sandy, gravelly or loamy soil; tolerates poor soil and a broad pH range. Avoid waterlogged ground and heavy clay without effective drainage.

Height

2-3 ft (0.6-0.9 m)

Spread

3-5 ft (0.9-1.5 m)

Foliage

Evergreen. Short, pointed, silver-blue needles packed closely along the shoots; prickly to handle and sometimes slightly purplish in winter.

Growth

Slow; often adds only a few inches each year and can take 10 years or more to approach its mature size.

Care needed

Low

• Deer resistant
• Drought tolerant
• Cold hardy
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   1.7 ft (0.53 m)

3. After 2 years

   1.8 ft (0.56 m)

4. After 3 years

   1.9 ft (0.59 m)

5. After 5 years

   2.2 ft (0.66 m)

About 8 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Growth rate

Slow

• Plant with the root flare at soil level and leave enough room for the mature spread.
• Water deeply through the first growing season whenever the root zone begins to dry; do not keep it constantly damp.
• Keep mulch clear of the crown and lower branches; gravel mulch suits well-drained sites.
• Skip routine feeding in ordinary garden soil; use a light spring feed only if growth is weak and nutrient deficiency is likely.
• Keep lawn sprinklers from repeatedly wetting the foliage, and avoid crowding it with taller plants.

Pruning. Prune only to remove dead, damaged or misplaced shoots in spring, preferably during dry weather. Cut back to a leafy side shoot; bare old wood usually does not regrow, so avoid hard pruning or shearing.

Early spring

Check for winter damage and remove broken or dead shoots during dry weather.

Spring

Plant in well-drained soil, water thoroughly and keep mulch away from the crown.

Late spring

Inspect shoot tips for browning; remove affected growth and check drainage before applying any treatment.

Summer

Water young plants during dry spells and inspect dusty or bronzed foliage for spider mites.

Autumn

Clear fallen leaves from the foliage and check that surface water drains away from the plant.

Winter

Gently lift off heavy, loose snow before it splays the branches; leave ice to melt naturally.

• Use as a low silver-blue mound among rocks and gravel, leaving space around it to show its shape.
• Repeat along a sunny border with creeping thyme and stonecrops for contrasting textures and low water needs.
• Pair with purple-leaved or golden-foliaged shrubs for year-round colour contrast.
• Grow in a large, frost-resistant container with free-draining compost and unobstructed drainage holes.

Garden styles it suits: Dry gravel garden, Low-maintenance, Winter interest, Alpine rock garden, Contemporary minimal and Small-space.

Plant it with: English lavender, Creeping thyme, Blue fescue, Creeping stonecrop and Dwarf mountain pine.

Wildlife: Dense foliage provides shelter for small birds and invertebrates. It offers little nectar or pollen value to pollinators.

• Root rot in wet soil: improve drainage or move the plant to a better-drained site; severely affected plants rarely recover.
• Fungal tip blight: prune affected shoots back into healthy growth during dry weather, clean tools between cuts and avoid overhead watering.
• Spider mites in hot, dry conditions: check for fine webbing and stippled foliage; rinse foliage occasionally in the morning and use a labelled treatment only if infestation persists.
• Bagworms, particularly in parts of the United States: pick off and destroy bags before eggs hatch; treat young larvae with a locally approved product if needed.

Do not eat the foliage or berry-like cones. Junipers can cause digestive upset if eaten by people, cats or dogs, but toxicity information specific to this cultivar is limited, including for horses. Keep livestock from browsing it and seek veterinary advice after significant ingestion. Prickly foliage and sap may irritate skin; wear gloves when handling.

• Blue Carpet juniper (Juniperus squamata 'Blue Carpet')

  Has similar prickly blue foliage but forms a much flatter, wider carpet rather than a compact rounded mound.

• Blue Chip creeping juniper (Juniperus horizontalis 'Blue Chip')

  Spreads low across the ground with long trailing branches and predominantly scale-like foliage, unlike Blue Star's dense, pointed needles.

• Dwarf Japanese garden juniper (Juniperus procumbens 'Nana')

  Forms a broader, ground-hugging mat with more obvious spreading branches and generally greener or blue-green foliage.

Juniperus is the Latin name for juniper, squamata means scaly and refers to the bark, and 'Blue Star' describes the blue, star-like clusters of needles.

Propagation. Take semi-ripe cuttings with a small heel of older wood in late summer or early autumn; rooting can be slow. Seed will not reliably produce plants identical to 'Blue Star'.

Accepted botanical name

Juniperus squamata

Native range

Afghanistan, Assam, China North-Central, China South-Central, China Southeast, East Himalaya, Myanmar, Nepal, Pakistan, Qinghai, Tibet and West Himalaya.

Measured

Average height 650 cm.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.