Blue Rug Juniper Juniperus horizontalis 'Wiltonii'

'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.