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Blue Rug Juniper

Juniperus horizontalis (jew-NIP-er-us hor-ih-zon-TAL-iss)

Family: Cupressaceae Unknown Groundcover (<1 ft)

'Wiltonii' is a low-growing, woody, needled evergreen shrub in the Cupressaceae (cypress) family. The parent plant is native to the northern part of North America. This cultivar is from a natural mutation discovered in Maine by Jacob van Heiningen of South Wilton, Connecticut, in the United States. The showy blue needles and its coverage give it the common name blue rug. It grows as a dense, creeping form to a diminutive height of 4 to 6 inches and width of 4 to 6 feet. This plant prefers full sun and well-drained, acidic to slightly alkaline soils. It is drought and deer tolerant, wind tolerant, fairly salt tolerant, and grows well in coastal conditions. It tolerates hot weather, moderately poor soils, and many air pollutants found in urban areas. It will adapt to the cold, snow, and frost of North Carolina’s colder regions. It also performs well in high desert locations where the temperatures fluctuate rapidly. Blue rug juniper takes on a purple tinge in winter. Many juniper varieties require moisture and cannot survive on sunny slopes where runoff can leave the soil dry. 'Wiltonii' does not require the moisture of other cultivars, making it a great solution for dry, sunny, sloped conditions, or in a drought-tolerant garden. Place along a retaining wall, in the front of a border, or along a walkway or patio where the foliage will provide year-round cover and interest. Quick ID Hints: 100% of leaves are scale leaves and silver-blue in color Leaves grow on only one side of stems Spray is fine-textured and plume-like Branches are long and floppy, forming dense mats The plant produces female cones that are 1/4" in diameter, globose, bluish or greenish-black, and glaucous Insects, Diseases, and Other Plant Problems: Creeping juniper is subject to infestation by aphids, bagworms, caterpillars, false spider mites, juniper and other scales, juniper tip mite, juniper webworm, and spruce spider mites. It is also susceptible to blights and some fungal diseases. A wet location may cause root rot. The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common juniper diseases and insect pests. VIDEO Created by Elizabeth Meyer for " Trees, Shrubs and Conifers " a plant identification course offered in partnership with Longwood Gardens. More information on Juniperus horizontalis .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 42 attributes.

How it fits the guild

Guild layer 5 - Groundcover (<1 ft) Optimal soil pH Acid (<6.0); Alkaline (>8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Erica carnea Juniperus horizontalis 'Plumosa' Salvia rosmarinus
Native alternatives Juniperus communis var. depressa

Full plant profile

Growing Conditions
Plant type
Ground Cover; Perennial; Shrub
Life cycle
Woody
USDA zones
4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Clay; Loam (Silt); Sand; Shallow Rocky
Soil pH
Acid (<6.0); Alkaline (>8.0)
Soil drainage
Good Drainage
Available space
12 inches-3 feet; 3 feet-6 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 0 ft. 4 in. - 0 ft. 6 in. | Width: 4 ft. 0 in. - 6 ft. 0 in.
Growth rate
Rapid
Maintenance
Low
Canopy layer
5 - Groundcover (<1 ft)
Form & Appearance
Habit / form
Creeping; Prostrate; Spreading
Texture
Fine
Foliage
Needled Evergreen
Leaf color
Blue; Gray/Silver
Leaf type
Needles
Leaf value
Showy
Hairs present
No
Leaf detail
All leaves are scale leaves. They are intense silver-blue in color, are closely appressed to stem, and grow on only one side of the stem. The spray is fine-textured and plume-like. Needels turn purplish in the winter.
Fall color
Purple/Lavender
Flower detail
No flowers
Fruit color
Black; Blue
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
No fruits. Plant produces female cones that are 1/4" in diameter, globose, and bluish or greenish-black and glaucous in color.
Stem detail
Branches are very long and floppy and form large, dense mats.
Wildlife & Ecology
Native status
Unknown
Landscape Use
Landscape location
Patio; Rock Wall; Slope/Bank; Walkways
Landscape theme
Drought Tolerant Garden; Rock Garden; Winter Garden
Design feature
Border; Mass Planting
Garden tags
#evergreen #deer resistant #evergreen shrub #wind tolerant #groundcover #drought tolerant #full sun tolerant #fantz #salt tolerant #well-drained soil #fast growing #frost tolerant #rocky soils tolerant #air pollution tolerant #dry soils tolerant #erosion control #urban conditions tolerant #winter interest #blue needles #garden walls #evergreen groundcover #purple needles #year-round interest #rock garden #border front #patio #cpp #poor soil tolerant #walkway
Problems & Resistance
Insect problems
Juniper Pest Management Calendar; Pests of Conifers
Resistant to
Deer; Erosion; Salt; Urban Conditions; Wind

Planted at Hunnicutt

Nobody’s planted this one yet.