Blue Rug Juniper
"Behold the junipers, shagged with ice."
-Wallace Stevens
(1879-1955)
(1879-1955)
'Blue Rug' Creeping or Carpet Juniper (Juniperus horizontalis 'Wiltoni') is the most commonly offered carpet juniper. It is only about six or eight inches tall with feathery glaucus (bluish) needles. Ultra cold-hardy to minus forty degrees Fahrenheit or even colder, in seriously cold winters it can turn almost purple. But it tends to be year-round green in very mild temperate zones like ours.
Dioecious, the male & female shrubs are separate. The male shrubs have rather dry yellow cones one-fourth inch around. The female shrub has fleshy dark blue berry-like cones. The female "berries" were used by Native Americans to brew a tonic tea, & they are also eaten by grouse, wood rats, & deer.
It wants full sun & will creep about in a leggier manner if stuck in the shade. Branches can extend over the ground a foot or even fifteen inches a year. Skillful pruning will cause the shrub to develop more branches resulting in denser groundcover as it spreads. It's highly drought tolerant after its first year, but not injured if it is in a well watered landscape so long as the soil drains well.It is an especially refined choice for uneven hillsides, as it will grow in a cascading manner downhill, conforming to the shape of the ground. A specimen of several years age is shown in these photos in March, creeping down a slope at the sunny front edge of a property for which I've done some landscaping. If grown in a large hanging basket or tall container, it would likewise seek the downward path.
Hardy as all hell, it tolerates dry conditions, cold conditions, moist conditions, urban pollution, hard or gravelly soils, maritime salt-air environments, just about anything except shade or poor drainage.
It propogates easily by layering. Select a long branch that might have been pruned back anyway. "Girdle" the selected branch; i.e., remove the bark from around what you want to become a new plant, but don't sever the limb. Turn the tip upward, stake it upright, & bury the girdled portion; a little rooting hormone on the girdle can help. The following spring it should be well enough rooted to cut it free from the parent. It can also be propogated from summer's softwood cuttings.
It is all but useless to try to grow them from seeds, which can take up to five years merely to germinate, hence no pressing reason to plant both a male & a female shrub.