Juniperus horizontalis 'Blue Rug' - aka Juniperus horizontalis 'Wiltoni'
Overall Description
A
very flat growing form of juniper with long trailing branches reaching
up to 8 ft in length. Foliage is a nice silvery blue color, and takes
on a very slight "purplish" tinge during winter months. Has excellent heat
tolerance, and can thrive in very adverse growing conditions. Has
become a very popular juniper groundcover since it was first introduced
back in 1914 by South Wilton Nurseries in Wilton, CT ( hence the 'Wiltoni' name mentioned above ). Established plantings produce silvery blue cones as well
that are approximately 1/4" in diameter. Great for use as a low
maintenance groundcover - especially in places where other groundcovers
have failed.
Typical spacing for most solid groundcover applications will be between 2-3 ft apart, but exact distance will vary depending upon exact planting location, sun exposure, area of the country, etc.
Plant Facts & Specifications
Mature Height: 4-6 inches
Mature Width: 5-8 ft
Growth rate: Moderate ( 4"-8" avg per yr )
Hardiness Zones: 4-9 ( if unsure of your zone, please use zone finder below )
Sun Exposure: Full sun to partial shade. Growth rate will be slightly slower in shadier spots.
Soil Preference: Average to slightly acidic & sandy - well drained. Mulching recommended.
Foliage Color & Texture: Silvery blue / green
foliage is similar to most typical groundcover junipers. Heavy texture with good color year round - slight purple cast in extremely cold climates during the winter. Purple cast will quickly change back to normal color with the onset of warmer temps in the spring.
Flower, Cone, Or Berry Facts: Very old, mature specimens have been known to produce a few cones here & there. Cones are silvery blue in color, and are about 1/4" in diameter.
Diseases / Insects:
Rather trouble free juniper - however Phomopsis has been observed on specimens that have been kept in very wet
conditions, or in soil with inadequate drainage. Occasional spider mite infestations have been observed as well.
Fertilization / Feeding: Either
water soluble ( Miracle Gro, or equivalent ), or granular ( Holly Tone
is excellent ). Other granular types with 6-12-12, or 10-10-10 ratio is
acceptable. Best to fertilize in early spring, and again in mid fall -
avoid feeding during hot summer months, and directly after
transplanting. 
