Low growing blue juniper

Juniper Groundcovers

Shore juniper growing on a bank.
Karen Russ, ©2008 HGIC, Clemson Extension

There are more than 170 species and varieties of juniper (Juniperus species) available in nurseries. Some of the most commonly grown junipers include Chinese juniper (J. chinensis), creeping juniper (J. horizontalis), savin (J. sabina), Japanese juniper (J. procumbens), and shore juniper (J. conferta).

Description

Junipers are evergreen, coniferous plants, ranging from low-growing shrubs to tall, slender trees. On young plants the leaves are usually needle-shaped and borne in threes. On adult plants leaves generally are small, scale-like, opposite and pressed close to the twigs. The color of the foliage will vary from light to dark green, blue to silver and yellow to gold. The flowers are not very showy and the fruits are berrylike, fleshy cones. Male flowers and female (berry-producing) flowers occur on different plants.

Landscape Use

Junipers are popular because of their numerous design characteristics: form, size, color and texture. Low-growing junipers can be used as groundcovers or foundation plantings. Taller-growing plants are excellent for screens, hedges or windbreaks. You can find a juniper in almost any height, width, shape or needle color. They grow throughout South Carolina, in a wide variety of habitats.

Needle texture of shore juniper
Karen Russ, ©2008 HGIC, Clemson Extension

One common trait shared by junipers is their tolerance to adverse conditions. Junipers generally enjoy full sun and good drainage. During summer droughts they withstand heat and dry conditions much better than most ornamentals.

The groundcover group includes types ranging from a few inches to 2 to 3 feet high.

Some species, such as creeping juniper, spread 5 to 6 feet. Others only spread 18 inches. Spacing of the plants depends on the species used. During the first years after planting, mulch will help keep the soil cool and the weeds down.

Junipers do not tolerate severe pruning. Do not cut back to older, needle-less wood. Propagate junipers by cuttings, seed, layering and grafting.

Problems

Junipers are subject to a number of pests and diseases. Among the most serious pests are bagworms (foliage is stripped), twig borers (branch tips turn brown and die), juniper scale (no new growth and foliage yellowed) and juniper webworm (webbing together and browning of foliage). Spider mites, leaf miners and aphids may also attack junipers. All of these can be controlled with a recommended pesticide.

The following fungal diseases may occur on juniper:

  • Cedar apple rust. This disease alternates between junipers and apple trees, producing galls and causing twig dieback.
  • Foliage or tip blight.
  • Phomopsis dieback. Dieback of leaves and twigs occurs in the spring. Eventually leaves may shed.
  • Root rots, caused by the fungi Pythium and Phytophthora. The root cortex sloughs off, roots rot and the entire plant dies.

These diseases may be prevented by growing disease-resistant cultivars.

Junipers resistant to phomopsis twig blight and cedar rusts are the Chinese juniper cultivars ‘Femina, ‘ ‘Keteleeri,’ ‘Mint Julep’and ‘Pfitzeriana’; common juniper cultivars ‘ Aureospica,’ ‘Suecica,’ ‘Broadmoor,’ ‘Knap Hill’ and ‘Skandia’; Eastern red cedar cultivar ‘Tripartita’; and creeping juniper cultivars ‘Wiltoni’ (‘Blue Rug’) and ‘Plumosa’ (‘Andorra’). Control may be obtained by using a recommended fungicide.

The following list of junipers describes a few that are well suited for a South Carolina landscape.

‘Bar Harbor’ creeping juniper.
Karen Russ, ©2008 HGIC, Clemson Extension

  • Chinese juniper (J. chinensis). Grows very large (50 to 60 feet in height and 15 to 20 feet in spread) with an erect, conical narrow tree form.
  • J. chinensis ‘Procumbens’ or Japanese garden juniper grows to a height of 2 feet and spreads 12 to 20 feet. Plants have feathery, blue-green foliage on long, wide-spreading, stiff branches.
  • Common juniper (J. communis) grows 10 to 12 feet tall with an 8- to 12-foot spread. Common Juniper has reddish-brown bark and gray-green foliage. Several cultivars are available.
  • Shore juniper (J. conferta) is a favorite groundcover, which should be planted 5 to 6 feet apart. Plants grow 12 to 18 inches high with a 6- to 8-foot spread. ‘Blue Pacific’ has ocean green foliage and is heat tolerant. ‘Emerald Sea’ is bright green. Shore juniper makes an excellent groundcover near the seashore because it is salt-tolerant.
  • Creeping juniper (J. horizontalis) is mainly used as a groundcover, since it grows up to 2 feet high with a 6- to 8-foot spread. There are many landscape uses with different cultivars.
  • ‘Bar Harbor’ is low spreading and fast growing. Feathery, blue-gray foliage turns plum color in winter. It tolerates salt spray.
  • ‘Plumosa’ or ‘Andorra creeping juniper’ is 2 feet by 10 feet, creeping, gray green in summer and plum color in winter.
  • ‘Wiltonii’ or ‘Blue Rug’ is 4 inches high by 8 to 10 feet wide, very flat and creeping. The foliage is an intense silver blue.
  • Eastern red cedar (J. virginiana) is a picturesque tree with dark green foliage that turns reddish in cold weather. The tree grows to a height of 40 to 50 feet, tolerates drought and poor soil. Small trees are Christmas tree favorites.
  • Southern red cedar (J. silicicola) is very similar to Eastern red cedar, though often more open and wide-spreading. This tree is salt-tolerant and grows well in sandy soils. It is well suited for coastal conditions.

More information on juniper shrubs and trees is available by requesting HGIC 1068, Juniper.

Juniper Ground Covers

SERIES 17 | Episode 08

There are places in the garden where you need a good, tough, weed suppressing groundcover. When it comes to that sort of plant you can’t beat ground-covering junipers.

Junipers are trees and shrubs native to the northern hemisphere. They are members of the cupressus family. They are used in gardens to give a good evergreen cover. The evergreen foliage can change during the season, so it can go from bluey-greys during summer to quite steely greys during winter.

Look out for Juniperus horizontalis ‘Douglasii’ which has a steely-grey foliage. What makes them such wonderful groundcover plants is that each layer of foliage grows on top of the one below, so they become quite dense. That means not much light gets to the ground and they suppress weeds.

A favourite is Juniperus conferta, native to Japan, where it grows on sand dunes. It forms a wonderful cover and it has a fresh green colour which is reminiscent of lawn. The foliage is really prickly, and that’s a characteristic of many junipers. Most are pretty tolerant with soils, but they don’t like waterlogging. Many will take quite alkaline conditions too.

Look out for a form of Juniperus sabina called Juniperus ‘Tamariscifolia’ which shows two foliage forms, an old leaf form and a young leaf form and this is quite typical of junipers. Another great thing about junipers is they tolerate shade cast over them by trees.

If you’re looking for a low maintenance solution for part of your garden, then junipers could be the plants for you.

Plant Database

Habitat

  • zone 4
  • native to northern North America
  • often found on gravely slopes and rocky seaside locations

Habit and Form

  • dense, evergreen shrub
  • branches very long and flexible
  • branches form large mats
  • 1′ to 2′ tall and 4′ to 8′ wide
  • medium growth rate
  • medium texture

Summer Foliage

  • glaucous needles
  • two kinds of needles: awl-shaped and scale-like
  • scales are closely pressed to stem and found in a four rank pattern
  • awls are found in opposite pairs
  • needle tip sharply pointed
  • green to blue-green

Autumn Foliage

  • evergreen, no fall color
  • needles turn somewhat purple in cold months

Flowers

  • dioecious
  • no ornamental value

Fruit

  • 2 to 3-seeded berry-like cone
  • found on recurved stalks
  • 0.25″ to 0.33″ in diameter
  • blue in color

Bark

  • reddish brown and peeling
  • hard to see because of overlapping branches

Culture

  • easily transplanted
  • adaptable to most conditions
  • full sun
  • pH adaptable
  • salt tolerant

Landscape Use

  • groundcover
  • erosion control
  • planters
  • mass plantings

Liabilities

  • Juniper blight and spider mites do cause some problems

ID Features

  • two types of leaves present
  • purple winter color
  • needles pointed
  • loose and floppy branches
  • blue-green summer color
  • spreading growth habit

Propagation

  • by cuttings

Cultivars/Varieties

‘Bar Harbor’ – A good, prostrate groundcover, this plant has blue-gray foliage in summer that shades blue-purple in the winter. It grows about 1′ tall and spreads to 6′ wide. It is a male clone, but several clones may be in the trade under the name ‘Bar Harbor’. This cultivar originated from Mt. Desert Island, Maine. It is a proven groundcover that is tolerant of salt spray and fast growing.

‘Blue Chip’ – This prostrate grower maintains its steel-blue foliage all year and grows 8′ to 10′ wide, but only 8″ to 10″ tall. It may be more sensitive to Phomopsis blight than other types.

‘Blue Prince’ – This selection out of Alberta, Canada possesses very fine blue needle color. It is a low, ground-hugging form growing 6″ tall and up to 5′ wide.

‘Hughes’ – The silver-blue foliage of this selection turns slightly purple in the winter. It grows 9′ wide and 1′ tall with distinct radial branching.

‘Mother Lode’ – This sport of ‘Wiltonii’ has distinctive gold variegated foliage. The yellow portion of the leaves turns orangish come winter. It grows slowly and hugs the ground, spreading 4″ to 6″ per year and reaching only 3″ tall with a spread of 3′.

‘Plumosa’ – Known as the “Andorra Juniper”, this is one of the most common landscape junipers despite its susceptibility to blight. It is a dense, compact grower reaching 2′ tall and up to 10′ wide. The summer foliage is bluish-green, becoming more purplish in winter.

‘Plumosa Compacta’ and ‘Plumosa Compacta Youngstown’ – These forms appear to be identical, appearing as dwarf forms of ‘Plumosa’ with a dense, flat growth habit to 18″ tall and many feet wide. The foliage is gray-green and deepens to purple in winter.

‘Prince of Wales’ – This cold hardy selection out of Canada forms a low mat 6″ high with bright green foliage that tinges slightly purple in winter.

‘Wiltoni’ (also known as ‘Wiltonii’ and ‘Blue Rug’) – This is perhaps the standard against which all other low, prostrate junipers are to be judged. It forms a dense mat of blue foliage 4″-6″ high and up to 5′ wide. The foliage turns slightly purple in winter exposure. This plant has proven very useful when used as a groundcover or bank planting. It was originally found on Vinalhaven Island in Penobscot Bay, Maine and introduced by South Wilton Nurseries, Wilton, CT. It is very salt and wind tolerant.

Juniper Shrubs: How To Take Care Of Junipers

Juniper shrubs (Juniperus) provide the landscape with well defined structure and a fresh fragrance that few other shrubs can match. The care of juniper shrubbery is easy because they never need pruning to maintain their attractive shape and tolerate adverse conditions without complaint. Anyone interested in providing habitat for wildlife should consider growing junipers. The National Wildlife Federation counts juniper shrubs as one of the top 10 plants for wildlife because they provide an abundance of food, shelter from harsh weather, and nesting sites for birds.

Juniper Info

There are more than 170 cultivated varieties of juniper, including low-growing ground cover or edging plants, shrubs and trees. The shapes include narrow columns, tight pyramids, and rounded forms that spread as wide as their height or more.

The fragrant foliage can be either needles or overlapping scales. Some shrubs have both

types of foliage because the leaves start out as needles and transition to scales as they mature.

Juniper shrubs are either male or female. The male flowers provide the pollen for the female flowers, and once pollinated, the females produce berries or cones. One male shrub can provide pollen for several females.

How to Take Care of Junipers

Plant juniper shrubs in a location with full sun or light shade. When they get too much shade, the branches spread apart in an effort to let more sunlight in, and the damage to their shape can’t be repaired.

Junipers grow in any type of soil as long as it is well-drained. Many types make excellent street shrubs because they tolerate the spray from road salt and other urban pollution.

Plant container-grown junipers any time of year. Shrubs with balled and burlaped roots are best planted in fall. Dig the planting hole as deep as the root ball and two to three times wider. Set the shrub in the hole so the soil line on the stem is even with the surrounding soil. Backfill with the soil removed from the hole without amendments. Press down firmly as you fill the hole to remove air pockets. Water deeply after planting, and add additional soil if it settles into a depression.

Water young shrubs during dry spells for the first two years. Afterward, the shrub is drought tolerant and can make do with what nature provides.

Fertilize the shrub with 10-10-10 fertilizer in spring of the year after planting and every other year thereafter.

JUNIPER

People plant junipers for two main reasons. First, they’re toughthey tolerate drought and almost any soil, and they’re hard to kill. Second, they come in many formsground covers, shrubs, columns, or treesand their needlelike foliage may be green, gold, gray, or various shades of blue. That’s the good.

On the down side, junipers seem to be the number one choice for landscaping hotels, office buildings, shopping malls, gas stations, and highway medians. Using lots of them can give your yard a distinctly commercial look. But if you don’t mind your home resembling a galleria, feel free.

Ground covers. This group includes low, spreading plants from a few inches to a few feet high. It takes a planting several years to fill in completely, so for the first few years, mulch between plants to keep down weeds. You’ll see how important this is if you ever have to reach into prickly juniper foliage to pull weeds.

Shrub types. These plants usually grow wider than tall and range from about 2 feet to more than 10 feet tall. Shapes include mounding, gracefully spreading, weeping, and weirdly twisted.

Columnar types. These upright growers have dense, pyramidal to conical shapes and are often used as vertical accents. (Planting them on the corners of your house, though, can make it look like King Arthur’s castle.) They grow from about 625 feet tall.

Tree types. These picturesque plants love chalky soil. Spread by birds, they dot the Southern countryside. Single trees become stately. Groups make handsome windbreaks and allees and are classic plants for lining a long driveway.

In many cases, junipers are best known by their selections. Pure species are seldom seen.

ozark white cedar, ashe juniper

juniperus ashei

  • Tree.
  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to south-central U.S. and northern Mexico.
  • Common juniper of Texas Hill Country.
  • Irregular or spherical crown to 20 feet tall and wide.
  • Trunk often divides near the base.
  • Gray-green foliage.
  • Shredding gray bark.
  • Female plants bear blue, – to -inch berries with a waxy sheen.
  • Likes dry, chalky soil.
  • Immune to cedar-apple rust.
  • Pollen of male plants can trigger allergies.

chinese juniper

juniperus chinensis

  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to northeast Asia.

Blue Point

  • Columnar.
  • Broad column to 12 feet tall by 8 feet wide.
  • Dense, blue-green foliage.

HETZ CHINESE JUNIPER

Hetzii(Juniperus chinensis ‘Hetzii’ )

  • Shrub.
  • Inverted pyramid to 15 feet tall and wide.
  • Blue-gray foliage.
  • Branches spread outward and upward at 45 angle.

Kaizuka

  • (‘Torulosa’ ).
  • HOLLYWOOD JUNIPER.
  • Shrub.
  • Irregular, upright to 20 feet tall by 10 feet wide.
  • Rich, green foliage with soft texture.
  • Branches have outlandish, twisted appearance.
  • Give it plenty of room.
  • Good in large containers.
  • Tolerates salt spray.
  • Variegated Kaizuka (‘Kaizuka Variegata’) has foliage splashed with creamy white.

Robusta Green

  • Columnar.
  • Irregular column to 1218 feet tall by 57 feet wide.
  • Brilliant, green, dense foliage.

San Jose

  • Ground cover.
  • Prostrate, dense, and spreading to 2 feet tall by 6 feet or more wide.
  • Dark green foliage.
  • Heavy trunked; slow growing.

Spartan

  • Columnar.
  • Pyramidal to columnar to 20 feet tall by 34 feet wide.
  • Rich green, dense foliage.
  • Fastgrowing, very handsome plant.

juniperus c

juniperus davurica ‘Parsonii

  • Ground cover.
  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to Asia, Siberia, and possibly Japan.
  • Spreading to 1 feet tall by 8 feet or more wide.
  • Rich sprays of dark green needles on slender branches.
  • One of the best junipers for the Southeast.

creeping juniper

juniperus horizontalis

  • Zones US, MS, LS, CS; USDA 6-9 unless noted.
  • Native to Canada and northern U.S.

Bar Harbor

  • Ground cover.
  • Ground-hugging, creeping to 1 feet tall by 8 feet or more wide.
  • Fast growing.
  • Feathery, blue-gray foliage turns purple in winter.
  • Tolerates salt spray.

Icee Blue

  • Ground cover.
  • Creeping, very flat to 4 inches tall by 68 feet wide.
  • A marked improvement over ‘Wiltonii’; intense silvery and denser foliage.

andorra creeping juniper

Plumosa

  • Ground cover.
  • Creeping to 1 feet tall by 10 feet wide.
  • Plumy foliage is gray-green in summer, plum-purple in winter.
  • Flat branches with upright branchlets.

Prince of Wales

  • Ground cover.
  • Creeping to 8 inches tall by 810 feet wide.
  • Medium green foliage turns purplish in fall.

blue rug creep- ing juniper

Wiltonii

  • Ground cover.
  • Very flat, creeping to 4 inches tall by 810 feet wide.
  • Silver blue foliage.
  • Long, trailing branches set with short, dense branchlets.
  • Like ‘ Bar Harbor’ but tighter; rarely shows limbs.

Yukon Belle

  • Zones US, MS, LS; USDA 6-8.
  • Ground cover.
  • Creeping to 6 inches tall by 68 feet wide.
  • Silvery blue foliage.
  • Extremely cold hardy.

PFITZER JUNIPER

juniperus x pfitzeriana(Juniperus chinensis ‘Pfitzeriana’ )

  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to northeast Asia.

Armstrong

  • Shrub.
  • Upright, dense to 4 feet tall by 5 feet wide.
  • Lacy, medium green foliage.

Gold Coast

  • Shrub.
  • Compact to 3 feet tall by 5 feet wide.
  • Soft, lacy, golden yellow foliage.

Mint Julep

  • Shrub.
  • Vase shaped to 46 feet tall by 6 feet wide.
  • Mint green foliage.
  • Arching branches.
  • Very attractive.

Pfitzeriana Aurea

  • Shrub.
  • Arching to 34 feet tall by 810 feet wide.
  • Greenish gray foliage; current seasons growth golden yellow.

Pfitzeriana Glauca

  • Shrub.
  • Arching to 56 feet tall by 1015 feet wide.
  • Silvery blue foliage.

Wilhelm Pfitzer

  • (‘Pfitzeriana’).
  • Shrub.
  • Arching to 56 feet tall by 1520 feet wide.
  • Feathery, gray-green, sharp-needled foliage.

japanese garden juniper

juniperus procumbens

  • Ground cover.
  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to Japan.
  • To 2 feet tall by 1220 feet wide.
  • Feathery yet substantial blue-green foliage on strong branches.

Nana

  • Ground cover.
  • To 1 feet tall by 68 feet wide.
  • Curved branches spreading in all directions.
  • Shorter needles and slower growth than species.
  • Can be staked into picturesque shrub.
  • Good in containers.

SHORE JUNIPER

juniperus rigida conferta(Juniperus conferta)

  • Ground cover.
  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to coastal Japan.
  • Prostrate, creeping to 1 feet tall by 10 feet wide.
  • Bright, soft green needles.
  • Excellent for seashore.
  • Takes sandy soil and salt spray.
  • Blue Pacific is denser, bluer, and more heat tolerant.
  • Emerald Sea is bright green.

savin juniper

juniperus sabina

  • Zones US, MS; USDA 6-7.
  • Native to central and southern Europe to central Asia.

Broadmoor

  • Ground cover.
  • Dense, mounding, and spreading to 23 feet tall by 10 feet wide.
  • Soft, bright green foliage.

Buffalo

  • Ground cover.
  • To 812 inches tall by 8 feet wide.
  • Soft, feathery, bright green foliage.

Tamariscifolia

  • Ground cover.
  • Symmetrically spreading to 1 feet tall by 1012 feet wide.
  • Dense, blue-green foliage.
  • Widely used.

rocky mountain juniper

juniperus scopulorum

  • Zones US, MS; USDA 6-7.
  • Native to western North America.

Blue Arrow

  • Columnar.
  • Very narrow to 1215 feet tall by 2 feet wide.
  • Tight, bright blue foliage.

Blue Creeper

  • Ground cover.
  • Spreading to 2 feet tall by 68 feet wide.
  • Bright blue-green foliage.

Blue Heaven

  • Columnar.
  • Neatly pyramidal to 20 feet high by 6 feet wide.
  • Foliage remains bright blue all year.

Gray Gleam

  • Columnar.
  • Symmetrical to 15 feet tall by 57 feet wide.
  • Silver-gray foliage.
  • Slow grower.
  • Tidy, formal-looking plant.

Pathfinder

  • Columnar.
  • Upright pyramid to 25 feet tall by 12 feet wide.
  • Blue-gray foliage; looser than ‘Gray Gleam’.

Skyrocket

  • Columnar.
  • Narrow spire to 1015 feet tall by 12 feet wide.
  • Blue-gray foliage.
  • Good vertical accent.

Tolleson’s Blue Weeping’. Shrub. Weeping to 20 feet tall by 10 feet wide.

Witchita Blue

  • Columnar.
  • Broad pyramid to 18 feet tall by 6 feet wide.
  • Bright blue foliage; very striking.

singleseed juniper

juniperus squamata

  • Zones US, MS; USDA 6-7.
  • Native to western China.

Blue Star

  • Shrub.
  • Mounding to 3 feet tall by 5 feet wide.
  • Squat, dense plant with silvery blue, sharp-pointed needles.

Chinese Silver

  • Shrub.
  • Dense pyramid to 7 feet tall by 4 feet wide.
  • Foliage is shiny blue.
  • Red, peeling bark.

Holger

  • Shrub.
  • Dense, spreading to 35 feet tall and wide.
  • Yellow new growth matures to blue-green.

eastern red cedar

juniperus virginiana

  • Tree.
  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to eastern North America.
  • Conical to broadly pyramidal to 4050 feet tall to 1530 feet wide.
  • Picturesque tree with dark green foliage that turns bronze in cold weather.
  • Tolerates drought, poor soil; thrives in limy soil.
  • Many selections sold.
  • Aromatic foliage and wood.
  • Female trees adorned with thousands of bright blue fruit.

Canaertii

  • Tree.
  • Upright pyramid to 20 feet tall.
  • Dark green foliage sets huge amount of blue fruit.

Emerald Sentinal

  • Tree.
  • Upright pyramid to 1525 feet tall by 58 feet wide.
  • Dark green foliage.
  • Useful hedge or screen.

juniperus v

  • siliciola.
  • SOUTHERN RED CEDAR.
  • Native to southern-most U.S. Zones MS, LS, CS, TS; USDA 7-9.
  • Tree.
  • Cone-shaped to 30 feet tall by 20 feet wide.
  • Very similar to the above species, though often more open and wide-spreading.
  • Grows in sand.
  • Frequently planted in rows and used as windbreak.
  • Tolerates seaside conditions.

Junipers take about any kind of soil as long as it is well drained. Wet soil causes root rot and death. Full sun is the rule. Very little trimming is needed if you choose a plant of the right size and shape to fill the allotted space. Deer seldom browse junipers, but the plants are subject to various pests and diseases. Among the most common are bagworms (foliage is stripped), spider mites (yellowing or browning needles with fine webbing present), cedar-apple rust (orange, jellylike galls in foliage), and tip blight (branch tips turn brown in spring).

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