Fundamental Facts
HARDINESS: Zones 3 to 9
PREFERRED SOIL pH: Adaptable
PREFERRED SOIL TYPE: Average, well-drained
PREFERRED LIGHT: Full sun
ATTRIBUTES: Hardy evergreens; use as foundation shrubs, accents, groundcovers
SEASON OF INTEREST: Year-round
FAVORITES: Choose locally adopted cultivars by size, shape, and color
QUIRKS: Grows poorly in wet soil
GOOD NEIGHBORS: Candytuft, daylily, spring-flowering bulbs
WHERE IT GROWS BEST: Full sun in any well-drained site
POTENTIAL PROBLEMS: Twig blight, bagworm, insect scale
PRUNING: Plants live decades; prune only to remove damaged branches
CRITTER RESISTANCE: Excellent
SOURCE: Nursery plants
DIMENSIONS: Varies with type, from 6 in (15.2 cm) to IS ft (4.6 m) high, and from 3 to 12 ft (1 to 3.7 m) wide
Juniper in the Landscape
Some type of juniper eventually wins a place in every care-free landscape. Adaptable and hardy, junipers ask only for sun and good soil drainage. They'll thrive for many years without pruning, watering, or other maintenance. These reliable evergreens endure cold winters with ease, many being hardy to climates as cold as those in Zone 3. And junipers come in so many forms and colors that there's bound to be exactly the right one for any site you have in mind.
Considering how tough they are, the gentle elegance that junipers bring to the landscape is nothing short of amazing. Although the scalelike evergreen foliage is scratchy to the touch, its density and fine texture combine to give junipers a soft appearance. Large, vase-shaped junipers will form a beautiful dark green backdrop for flowering perennials; compact cultivars can be used in foundation plantings. Low-growing junipers will knit themselves together into a lush, weed-resistant groundcover that's an ideal no-mow covering for slopes. In addition, there are upright columnar and pyramidal junipers that grow to tree size, providing wind breaks, or strong vertical structure for small spaces.
Getting to Know Junipers
With most garden plants, it makes sense to begin the selection process on the basis of plant names. However, this can lead to unnecessary confusion with junipers, because several major species compare closely in terms of hardiness, diversity of form, and practical use in the landscape. So, rather than sorting through hundreds of cultivar names, it's better to decide on a size, shape, and color, and then shop around to see what's available.
Depending on selection, junipers may be blackish green, medium grass green, blue-green, gray-green, or have bold chartreuse leaf tips. In cold climates where few other evergreens are present in the garden, dark-colored junipers are often preferred because of the rich green color they bring to the winter landscape. In areas where other evergreens are easily grown, gray-green or blue-green junipers are often used as accent plants. Be careful with gold-tipped junipers, however. Although they are an easy way to light up a green landscape, a little of their intense color usually goes a long way.
Sizing Up Junipers
The nursery industry does an excellent job of labeling junipers. Plant tags often include all the information you need to make a good selection. In the language of the trade, a vase-shaped plant grows into an inverted triangular shape, with stems that arch up and away from a central base. Those that grow less than 4 ft (1.2 m) tall and wide are top candidates for use as foundation shrubs, while larger vase-shaped junipers are best used as accent shrubs or grouped into a hedge for a sunny lawn.
Dozens of junipers exhibit what is called a spreading habit. These plants may grow less than 3 ft (1 m) tall, yet spread as wide as 10 ft (3 m).Their mature size can be difficult to imagine when you are looking at a small plant in a pot, but trust what the tag has to say. Spreading junipers can be used to flank walkways or cover gentle slopes, or stand alone as broad pools of evergreen color in an open lawn.
Groundcover junipers generally grow to less than 12 in (30.5 cm) tall, but each plant may spread to 10 ft (3 m) wide. There is much variation among cultivars in foliage color and winter hardiness, so it is wise to listen to advice on cultivars from local nursery experts. Excellent vigor is important, because stressed groundcover junipers may do a poor job of suppressing weeds. For example, fine-textured 'Blue Pacific' shore juniper tolerates salty soil, but it suffers from winter cold north of Zone 6. By comparison, 'Bar Harbor' trades its summer green for bronze red in winter and is hardy to Zone 3.
Upright junipers can be sorted into two shapes: straight columnar plants, which are often very narrow and up to 10 ft (3 m) tall, or symmetrical, pyramidal shapes that resemble Christmas trees. Unlike most evergreen trees, however, pyramidal junipers, such as bright green 'Hetzii Columnaris' or gray-green 'Silver Spreader', seldom exceed 15 ft (4.6 m) in height, making it easy to fit them into small landscapes. Columnar
junipers are so narrow that they can be used at the back of a flower border or planted near the corner of a house without interfering with traffic.
Growing Junipers
Junipers are easy to transplant in spring. Where winters are mild, you can also set them out in fall.To encourage the development of new roots, dig planting holes about twice as wide as the nursery container and at the same depth. After planting, provide water during dry spells as needed to keep the soil moist the first season. When planting spreading or ground-cover junipers, surround plants with a broad, thick mulch, such as bark chips or compost, to control weeds until they reach mature size. Hand-weed as needed, and refresh the mulch every few months to support this process.
Prune junipers only to remove damaged stems. The plants look best when allowed to follow their natural growth patterns, and severe pruning can result in brown patches that never fill out with fresh green growth.
Keeping Junipers Healthy
Most junipers grow for many years with no pest problems, but occasionally you may notice brown lantern-shaped twiggy sacs hanging from stems. These are the cocoonlike dwellings of the bagworm, a caterpil-
lar that eats juniper foliage. Remove and dispose of the bags by hand as soon as you spot them. Rarely, a fungal disease called twig blight causes stem tips to turn brown and die. Prune off and dispose of discolored branches. If the problem continues, spray plants with a commercial fungicide labeled for use on junipers, according to the directions on the package label. Juniper scale are tiny insects that hide and feed inside branch crevices, weakening the branches until they turn yellow. Less than 1/2 in (1.3 cm) long, immobile, and oval in shape, scale are usually white or light brown. Spray affected plants in late spring with a botanical neem-based insecticide, or use a commercial garden insecticide labeled for use for scale on junipers. Apply as directed on the package labels.
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