Tree · Cupressaceae
Juniper
Juniperus chinensis
Give it full sun and sharp drainage, and juniper brings quiet structure to a garden for the rest of its long life.
Full sun
Every 7–14 days
USDA 3–9
1–59 ft · 0.3–18 m
Overview
Juniper is the evergreen that lets a garden look composed with barely any fuss. A member of the cypress family found across the northern hemisphere, it holds its own through cold, heat, drought, salt, and thin soil, so the plot stays furnished when other shrubs fade. The forms range from flat groundcovers a foot high to upright trees reaching up to 59 feet (18 m), which makes it a natural anchor for a front bed, a boundary line, or a courtyard corner.
What earns juniper its place in a scheme is how quietly it works with the rest of a space. Set it in sun and free-draining ground and it holds its color through winter, so the view from a window stays green when the borders go bare, and it can screen a fence, edge a path, or stand alone as a sculptural presence that draws the eye. On female plants the berry-like blue cones ripen over about two years and invite birds close through the cold season, a small daily pleasure from the kitchen window.
One thing shapes how juniper fits into a design for the long run. It grows slowly and will not resprout from bare old wood, so the outline it takes in the early years is the one a room-with-a-view keeps looking at. Prune it lightly and often to hold the silhouette you want, rather than banking on a hard cut to reset it later.
Care
The short version: full sun and fast-draining soil carry the whole look. Water through the first year to settle the roots, then let it sit as an easy fixture in the scheme, feed it rarely, and prune only into green growth.
Light
Juniper looks its best in full sun, ideally 6 or more hours a day, though it accepts a little partial sun. Placed in real shade it thins, the color goes flat, and disease starts to show, so give it the open, bright spot in the scheme.
Water
Water a new juniper regularly through its first year to settle the roots into the bed. After that it is very drought tolerant and asks for help only in a long dry spell, since the one thing that undoes it is soggy soil.
Soil
Sharp drainage counts for far more than rich ground when you site a juniper. It takes to sandy, rocky, or clay soil as long as water moves through, and it stays content across a wide pH of 5.0 to 8.0, which opens up almost any corner of the garden.
Temperature
Few shrubs hold a scheme together through such extremes. Juniper takes everything from about -29°F to 100°F (-34°C to 38°C), keeping its foliage through hard winters and its poise through summer heat.
Humidity
Outdoor humidity is simply the weather, and juniper takes it in stride. Air movement matters more than any humidity level, since still, damp air around crowded foliage is what lets the tip blights spoil the look.
Feeding
Juniper rarely needs feeding to earn its keep. If the growth looks thin, a single light application of balanced or slow-release fertilizer in spring is enough, and overfeeding only works against the tidy habit.
Pruning
Shape it lightly in late spring and cut only into green growth, because bare old wood will not push new shoots and a deep cut leaves a gap in the silhouette that stays. Pull off dead, diseased, or blight-killed tips during dry weather to keep the outline clean.
Repotting
Container and bonsai junipers, the ones that dress a terrace or entrance, want fresh room every 2 to 3 years. Repot when roots circle the pot, water runs straight through, or growth slows with yellowing foliage.
Size & spacing
The forms range widely, spanning 1 to 59 feet (0.3 to 18 m) in height, with spreads of 2 to 20 feet (60 cm to 6 m). Match the cultivar to the room it has and leave each plant space for air to move through the canopy.
When to plant
Juniper is planted, not sown, and spring and fall are the natural moments to place it, when the soil works easily and the weather stays mild. Set it out in either season so the roots settle before summer heat or winter cold, and keep it watered through that first year while it finds its footing in the border.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring or fall
- Harvest: inconspicuous; blue berry-like female cones mature over about two years
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
A juniper set in the right spot stays handsome and trouble-free for years, so when the look slips it usually traces to wet soil or crowded, damp growth. Glance over the new tips, the inner foliage, and the branch lines, and match what you see below before reaching for a spray.
Whole plant thinning and quietly declining
A juniper left in wet ground falls to Phytophthora root rot, and the foliage thins, dulls, and loses its color from the top down. The roots blacken and rot, and by then there is rarely a way back. Correct the drainage, hold off the water, and replace any specimen too far gone to keep the planting looking its best.
Fix:
- Improve drainage and stop overwatering
- Plant in raised beds and amend heavy clay with porous material such as ground pine bark
- Remove severely affected plants, as root rot is difficult to reverse
New tips fading and dying back
Two fungal tip blights are usually behind those failing tips. Phomopsis tip blight settles into soft new growth during warm, wet spells, and Kabatina tip blight claims year-old twigs in spring through small wounds. Wait for a dry day to prune well below the dead tissue, wipe the shears clean between cuts, and thin the plant so air moves freely and the look stays crisp.
Fix:
- Prune out and destroy blighted tips well below the dead tissue during dry weather, disinfecting tools between cuts
- Improve air circulation by spacing and selective thinning
- Avoid overhead watering and wetting foliage
- Apply a labeled fungicide (mancozeb, thiophanate-methyl, or copper) protectively on new growth where blight is recurring
Needles stippled yellow with a whisper of webbing
Two small sap-feeders dull the foliage this way. Spruce spider mites stipple the needles and trail fine webbing in the cool of spring and fall, while juniper scale clings on as tiny bumps and yellows the whole plant. Tap a branch over white paper to catch the moving mites, then rinse them off with a firm jet of water or insecticidal soap, and reach for a dormant oil spray in late winter to settle the scale.
Fix:
- Dislodge mites with a strong spray of water
- Apply insecticidal soap or a labeled miticide for heavy mite infestations and preserve natural predators
- Apply 2-3 percent horticultural oil as a dormant spray in late winter for scale, or treat crawlers with a labeled insecticide
Spindle-shaped bags hanging along the branches
Those little carrot-shaped bags are the mark of bagworms, caterpillars that feed from inside a case they stitch together out of foliage. A heavy season can strip branches or take the whole plant, which no planting can afford. Pick the bags off through fall and winter to clear the overwintering eggs, then spray Bt in spring while the larvae are still small.
Fix:
- Handpick and destroy bags in fall and winter to remove overwintering eggs
- Apply Bacillus thuringiensis (Bt) in spring while larvae are young and small
- Use a labeled insecticide for heavy infestations of older larvae
Woody galls sprouting orange horns in spring
The strange galls belong to cedar-apple rust and its relatives, fungi that move between junipers and apple-family plants such as crabapple and hawthorn. They do little to the juniper's own good looks, so the point of acting is really to shield the fruit trees nearby. Cut the woody galls away before they release their orange horns, and set junipers well apart from apples and crabapples when you plan the garden.
Fix:
- Prune out and remove woody galls before they produce orange horns in spring
- Plant rust-resistant juniper cultivars
- Do not plant junipers within a few hundred yards of apples, crabapples, or hawthorns
- Apply a labeled fungicide (mancozeb or propiconazole) where control is needed, though galls do little harm to the juniper itself
Toxicity
Juniper is an easy plant to live alongside, whether the household runs to pets or to people. It carries none of the toxins on the standard poison lists, and its sharp, bitter foliage tends to keep animals from grazing it in the first place. The one thing worth keeping in mind is that the berry-like cones can mildly upset a stomach in quantity, and that only a few species are the true culinary juniper used to flavor gin.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Caution
Juniper poses no poisoning threat to cats, and its sharp, aromatic foliage tends to keep them out of the beds anyway. A cat that works through a lot of the berry-like cones may have a brief, mild stomach upset that passes on its own.
Dogs Caution
Dogs can share the garden with a juniper untroubled, since it carries none of the listed toxins. A mouthful of the cones or oily foliage rarely amounts to more than a little drooling or a loose stool for a day.
Horses Caution
The strong terpene scent makes juniper taste unwelcome, so horses generally leave it be. One that grazes a large helping of berries may feel a mild gut upset, though the plant is no poisoning risk.
Rabbits Caution
Rabbits seldom trouble the resinous needles, and juniper holds no toxin that endangers them. Keep any nibbling modest, since the volatile oils can loosen the gut in larger amounts.
Livestock Safe
Cattle, goats, and sheep tend to pass juniper by on account of its bitter, aromatic foliage, and it stays off the usual lists of plants that poison them.
Birds Safe
Birds feed on the ripe blue cones with pleasure and scatter the seed as they go, so the fruit is nothing but a welcome course for them.
People Edible with care
The cones of a select few species, chiefly Juniperus communis, are the spice that lends gin its signature note, yet ornamental landscape junipers are not all edible and some cones can upset the stomach. Keep culinary use to the known species, and wear gloves for the prickly, oily foliage.
The aromatic foliage and berry-like cones may cause mild, self-limiting stomach upset if eaten in quantity, and the prickly juvenile needles plus juniper oils can mildly irritate skin, so wear gloves when pruning. This is irritation, not poisoning.
Varieties
Junipers arrive in more shapes than almost any other evergreen, from creeping mats to pencil-thin columns, which is exactly why they slot so neatly into a considered planting. These are the forms you will meet most often at the nursery.
'Hetzii'
A generous, wide-spreading blue-green shrub that furnishes large foundation plantings and screens with an easy elegance.
'Sea Green'
A compact, fountain-shaped shrub whose arching branches and soft mint-green foliage settle into a graceful low hedge.
'Spartan'
A trim, dense, dark green column of about 15 to 20 feet tall and only around 5 feet wide, the poised choice for an upright screen.
'Hollywood' / 'Kaizuka'
An irregular, twisting upright dressed in rich green, prized as a living sculpture at the heart of a planting.
Juniperus scopulorum 'Skyrocket'
A pencil-thin blue-gray column slender enough to draw the eye upward in the tightest corner of a bed.
Juniperus squamata 'Blue Star'
A low mounding dwarf of 1 to 3 feet, cushioned in dense silvery blue-gray needles that read as a cool accent.
How to propagate
How you multiply a juniper comes down to the form you want to keep, since named cultivars will not come true from seed and have to be cloned another way.
Stem cuttingsModerate
Late fall through winter from semi-hardwood to hardwood growth · Several weeks to a few months to root
Most cultivars are raised from cuttings so the form stays true to the parent. Take semi-hardwood to hardwood pieces from late fall through winter, dip them in rooting hormone, and set them into well-drained media, where they root over several weeks to a few months.
GraftingDemanding
Winter under glass · Weeks to months
Grafting is the route for upright tree forms and choice cultivars that resist rooting from cuttings. Worked in winter under glass, it takes weeks to months to knit together, which keeps it in the hands of skilled growers.
LayeringEasy
Spring · Several months to a year
Layering is the simplest approach for the low, spreading kinds. Pin a trailing branch to the soil in spring and it roots in place over several months to a year, a natural fit for groundcover and shrub forms.
SeedDemanding
After cleaning and cold stratification · Slow and erratic, often more than a year to germinate
Seed serves for raising species rather than named cultivars, which do not come true this way. Clean the cones and give the seed a cold stratification, then wait, since germination is slow and erratic and often takes more than a year.
Myths
The berries on any landscape juniper can be gathered and eaten like the ones that flavor gin.
Only a few species, chiefly Juniperus communis, are grown as a culinary spice. Many ornamental junipers bear berry-like cones that taste poor and can bring on a mild stomach upset, so don't assume the berries on a landscape juniper are edible.
An overgrown juniper can be brought back by cutting it hard into the old bare wood.
Junipers will not send new shoots from old leafless wood, so a hard cut into bare branches leaves a lasting empty gap in the shape. Always prune into green, foliage-bearing growth and refine the form a little at a time.