Blue Chip juniper

Sun

Full sun; shade produces thinner growth and poorer foliage colour.

Water

Water regularly during establishment, allowing the soil to dry slightly between soakings. Drought tolerant once established; avoid persistently wet roots.

Soil

Well-drained sandy, gravelly or loamy soil; tolerates poor soil and a broad pH range. Heavy clay needs a raised planting position or improved drainage.

Height

0.5-1 ft (0.15-0.3 m)

Spread

6-8 ft (1.8-2.4 m)

Foliage

Evergreen. Fine, mostly scale-like silver-blue foliage on trailing branches, often becoming purplish or bronze-blue in cold weather.

Growth

Moderate; takes several years to form a broad carpet.

Care needed

Low

• Deer resistant
• Drought tolerant
• Cold hardy
• Heat tolerant
• Wildlife
• Fragrant

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

   0.2 ft (0.06 m)

2. After 1 year

   0.4 ft (0.12 m)

3. After 2 years

   0.6 ft (0.19 m)

4. After 3 years

   0.7 ft (0.22 m)

   full size

About 3 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

Native to

the US and Canada

Growth rate

Moderate

• Plant with the root flare at soil level and leave room for its mature spread.
• Water deeply during the first growing season whenever the root zone begins to dry.
• Keep weeds out while plants establish; use a thin mulch layer without piling it against stems.
• Do not feed routinely; use a light spring application of balanced fertiliser only if growth is weak and poor nutrition is likely.
• Keep lawn sprinklers and frequent irrigation away from established plants.

Pruning. In spring, remove dead or damaged branches and shorten stray shoots back to a leafy side branch. Avoid shearing or cutting into bare old wood, which usually does not regrow.

Early spring

Check for winter damage and remove dead branches once healthy growth is distinguishable.

Spring

Plant into well-drained soil and water thoroughly; weed around young plants.

Early summer

Shorten any shoots growing over paths, cutting back only into leafy growth.

Summer

Check newly planted shrubs during dry spells and inspect stressed foliage for mites.

Late summer

Take semi-ripe cuttings if you want more plants with the same foliage and habit.

Autumn

Clear fallen leaves from the foliage and check that water drains freely before winter.

• Plant across sunny slopes to create a low evergreen cover; control erosion separately until plants establish.
• Let branches trail over retaining walls or between large rocks.
• Repeat beside upright conifers or ornamental grasses for contrasting shapes.
• Use as a silver-blue ground layer in gravel gardens with drought-tolerant perennials.

Garden styles it suits: Low-maintenance, Dry gravel garden, Desert / xeriscape, Winter interest, Coastal and Modern.

Plant it with: Lavender, Catmint, Yarrow, Blue fescue, Upright stonecrop and Dwarf mugo pine.

Wildlife: Dense branches provide low shelter for small animals. Female plants may produce blue, berry-like cones that some birds eat; the inconspicuous pollen cones are wind-pollinated, so this is not a significant nectar plant.

• Root rot in waterlogged soil: improve drainage or move the plant to a raised site; badly rotted plants rarely recover.
• Juniper tip blight causing brown shoot tips: prune affected shoots in dry weather, clean tools and avoid overhead watering.
• Spider mites causing stippled, dull or bronzed foliage in hot, dry conditions: confirm mites by tapping foliage over white paper, then rinse foliage or use a labelled insecticidal soap.
• Brown, bare patches after shading or hard pruning: restore full sun and avoid cutting into leafless wood; replace plants if the bare framework will remain exposed.

Not generally considered highly poisonous, but foliage and berry-like cones contain oils that may cause stomach upset if eaten by people, cats or dogs. Sap and foliage can irritate sensitive skin. Horse-specific toxicity information for this cultivar is limited, so do not use it as forage or allow horses to eat prunings.

• Blue Rug juniper (Juniperus horizontalis 'Wiltonii')

  Usually forms a flatter, tighter carpet than 'Blue Chip', with less raised branching; young plants can be difficult to distinguish.

• Blue Pacific shore juniper (Juniperus conferta 'Blue Pacific')

  Has conspicuous, stiff, pointed needles rather than the predominantly scale-like foliage of 'Blue Chip'.

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

  Forms a compact, rounded mound with dense, prickly, starry needle clusters rather than long trailing branches.

The species name horizontalis refers to the plant's horizontally spreading branches, while 'Blue Chip' names its blue-foliaged cultivar.

Propagation. Root semi-ripe cuttings in late summer in a free-draining medium, or layer a low branch. Seed does not reliably reproduce the cultivar.

Accepted botanical name

Juniperus horizontalis

In the US and Canada

Native in Alaska, Canada, the lower 48 states and St. Pierre and Miquelon.

Native range

Alaska, Alberta, British Columbia, Colorado, Illinois, Iowa, Labrador, Manitoba, Masachusettes, Michigan, Minnesota and Montana.

Measured

Soil pH 5.5 to 7.8. Average height 76 cm.

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