Junipers are a large group of coniferous evergreen shrubs and trees that make excellent ornamental plants. Juniper plants are quite hardy and are capable of growing in some of the harshest environments on the planet, making them ideal for most gardens.
This article will explore every aspect of caring for juniper bushes and trees.
What are Junipers?
Juniper trees and shrubs are coniferous plants, which means that they produce cones. All junipers are evergreens that keep their foliage all year round. Juniper plants are members of the Cypress family and there are approximately 50 to 67 individual juniper species.
Juniper plants are widespread across the Northern Hemisphere. Junipers grow across the Mediterranean as well as central, southern, and western parts of Asia. In parts of the Himalayas, junipers grow high on the slopes of eastern Tibet, forming tree lines that are some of the highest in the world. Juniper species also grow in tropical and Southern regions of Africa as well as mountainous areas of Central America.
Junipers belong to the Cypress family (Cupressaceae). This family is part of the larger Coniferophyta or Pinophyta group known commonly as conifers. Juniper trees and shrubs form the Juniperus genus, which contains approximately 67 different juniper varieties. Juniperus communis, the Common Juniper, is the most well-known of these.
Appearance and Characteristics
Juniper plants can range from low, ground-spreading bushes and shrubs to large trees. All types of junipers are evergreens, meaning that they don’t lose their leaves. Junipers are also coniferous and form cones, which are a type of hard, woody fruit. These cones form the “berries” of a juniper bush.
Some juniper plants have two types of leaves. Younger branches produce needle-like foliage, which gradually flattens as the plant matures. The needles grow in groups of three that are joined together at the bottom of each cluster. Older juniper leaves have tiny overlapping scales that form the foliage. Other junipers, such as the Common Juniper, retain their needle-like leaves permanently.
Juniper foliage is predominantly green but can show hues of blue, gold, and silver. These colours gradually soften as the plant matures. Junipers can take up to 50 years to reach their full mature size.
- Care Level – Easy
- Sunlight – Full sun or partial shade
- Watering – Infrequent, sometimes not even necessary
- Humidity – Moderate
- Temperature – Cooler temperatures
- Soil – Most well-draining soils
- Soil pH – Slightly acidic (5.0 – 7.0)
- Fertiliser – Once every year or two
- Repotting – Every two or three years
- Pruning – Not essential
How to Care for Junipers
Juniper bushes and trees need either full sun or partial shade. Junipers should receive up to six hours of direct sunlight every day. These evergreens grow well in most garden aspects, whether it’s north or south-facing. Juniper plants cannot tolerate full shade as this can cause stunted growth.
Juniper plants are extremely drought-tolerant. Once established, junipers may require little to no extra watering. Juniper trees and shrubs do not tolerate over watering. If left in waterlogged soil, junipers will be more susceptible to root rot and other pests and diseases.
For junipers growing in containers, water when the upper three inches of soil have dried out. Young plants and seedlings need occasional watering during hot, dry periods. Junipers that have recently been planted should be watered every one to two weeks until the roots have been established.
- Humidity & Temperature
Juniper trees and bushes thrive in cooler temperatures. These evergreens prefer the conditions of the Northern Hemisphere. In the US, most juniper varieties grow well in USDA Zones 2 to 7. The majority of junipers can survive outside in the winter, but this depends on the exact cultivar. Juniper plants do best with moderate humidity.
Juniper plants don’t require much cleaning. Junipers are coniferous evergreen plants that don’t shed their leaves. Established juniper plants are extremely self-sufficient and won’t require much additional care.
- Fertiliser & Soil
Juniper shrubs and trees can grow in a wide range of soil types. These slow-growing coniferous plants grow naturally in poor, nutrient-deficient soils. Juniper plants require well-draining, slightly acidic soils with pH levels ranging from 5.0 to 7.0.
Juniper plants grow relatively slowly, taking up to 50 years to reach their mature size. Junipers don’t require supplemental fertilising to grow. However, fertiliser can be beneficial. Juniper trees and shrubs only require fertilising once every one or two years. Apply fertiliser during early spring. Use a balanced slow-release fertiliser with an NPK ratio of 10-10-10.
Junipers make excellent shrubs and trees for containers. Although junipers grow relatively slowly, they require a large pot. When planting junipers in containers, aim for a vessel that’s wider than the nursery pot by at least 8-inches. Juniper shrubs need repotting every two or three years into larger containers.
- Growing in the garden
Juniper plants grow well in most gardens across the Northern Hemisphere. Juniper shrubs and trees need a site that gets full sun or partial shade. Junipers grow well in most soil types as long as the medium is well-draining.
Juniper trees should be planted in the spring wherever possible. Here’s a step-by-step planting guide for juniper plants:
- Start by supplementing the soil with a small amount of organic matter such as compost.
- Excavate a hole that’s two or three times wider than the rootball. The hole also needs to be dug at the same depth as the rootball.
- Situate the plant in the hole with the rootball oriented slightly higher than the surrounding soil.
- Backfill the hole and tamp down to prevent air pockets from forming.
- Water the juniper plant in well. Continue to water once every one or two weeks until the juniper has established itself and is showing fresh growth.
Juniper shrubs and trees are fantastic ornamental plants for any garden. Juniper varieties range from ground-cover shrubs that only grow six inches tall to medium-sized bushes or large trees. Juniper hedges or trees make excellent additions to a garden ecosystem, providing food and nesting sites for birds and other wildlife.
How and When to Prune
Pruning isn’t actually required when caring for juniper plants. Juniper plants only require pruning when dead or diseased stems need to be removed. However, juniper bushes can be trimmed and shaped easily, making them ideal for topiary. Junipers do not respond well to excessive pruning.
Junipers should be pruned during the winter while the plant is in its dormant phase. Refrain from pruning the main trunk, which is known as the central leader. Avoid trimming mature scaled stems unless removing the entire branch because they won’t be able to form new growth.
When pruning junipers, only cut off small sections of foliage that have needles. To encourage fresh, bushy growth, prune stems back to just above a new bud. For juniper shrubs, restrict pruning to side branches that are growing vertically.
Problems with Juniper Plants
Although juniper plants are extremely hardy, they are still susceptible to some problems with pests or diseases. Here are the main issues to keep an eye on:
Some aphid species, such as giant conifer aphids, can target juniper plants. If the juniper’s leaves start to look brown or yellow, or if sooty mould appears, aphids may be present. Dislodge aphids using a hose and remove affected foliage.
- Bagworm caterpillars
Bagworm moth caterpillars emerge from nest sacs that resemble conifer cones. Each sac may contain hundreds of caterpillars. The larvae consume juniper leaves, which can kill younger plants. Remove the sacs before the eggs hatch or apply targeted caterpillar sprays.
- Juniper scale
Large-scale infestations of juniper scale insects can target and kill juniper plants. Wilting or dry-looking yellow or brown leaves are the main symptom of juniper scale. Use insecticidal soap to clear the pests before removing any affected foliage.
How to Propagate Juniper Plants
Juniper plants can be propagated through stem cuttings. Juniper shrubs and trees should be propagated in late summer. Here’s a brief guide on how to propagate junipers:
- Cut four to six-inch lengths away from stems with a slight brown colour to the wood. Make sure that the cuttings come from sections of foliage that have needles rather than scales.
- Remove any needles from the lower half of each cutting. Dip the end of each cutting in some rooting hormone.
- Place each cutting in a pot with a well-draining mix of perlite and multi-purpose compost.
- Keep each cutting moist, but not waterlogged. Situate the cuttings in a warm, sheltered area to help them develop roots. This can take between six and 12 weeks.
- Keep the cuttings growing in pots for at least a year before planting outside.
Common Juniper Types
- Common juniper (Juniperus communis)
The most well-known type of juniper, the common juniper has a native range stretching from North America to Central and Eastern Asia. This variety can grow as a ground-cover shrub or as a large tree. Many Common juniper cultivars possess an RHS Award of Garden Merit.
- Creeping juniper (Juniperus horizontalis)
As the name implies, this juniper variety forms a low-spreading ground-cover shrub. It can reach several meters in diameter. Creeping juniper is native to parts of Canada and North America. There is a range of cultivars available.
- Chinese juniper (Juniperus chinensis)
Chinese juniper grows as a large shrub or tree. This variety is indigenous to parts of Southeast Asia including China, Korea, and Japan. Chinese juniper can range in size from one to 20 meters tall. It is a popular ornamental variety and is also used for bonsai.
- Flaky juniper (Juniperus squamata)
This is another highly-prized ornamental variety thanks to its blueish foliage. Flaky juniper grows in high-altitude areas of Afghanistan and China. Varieties such as Juniperus squamata ‘Blue Star’ are dwarf cultivars that make excellent container plants.
- Himalayan juniper (Juniperus recurva)
Also known as drooping juniper, the cone-shaped growth habit of this variety makes it a stunning architectural addition to the garden. Himalayan juniper is native to high-altitude regions spanning India, Pakistan, and China. Juniperus recurva ‘Castelwellan’ is one of the most popular cultivars.
Facts About Junipers
- Family – Cupressaceae
- Subfamily – Cupressoideae
- Genus – Juniperus
How big does a Juniper bush get?
Juniper bushes can reach a variety of sizes. Some junipers form spreading ground-cover shrubs that are approximately six inches tall but spread for several meters. Other species grow into tall trees ranging from 20 to 40 meters high.
What are Juniper bushes good for?
Juniper bushes make excellent ornamental shrubs or trees for most gardens. Junipers can be shaped using topiary techniques to create statement features. Juniper bushes and trees are also good for wildlife, particularly as food sources and nesting sites for birds.
Are Juniper bushes poisonous?
Many juniper bushes produce berries that are safe to eat. However, some species such as Juniperus savina and Juniperus oxycedrus are poisonous and should not be consumed. Most junipers are also poisonous to dogs and cats.
How fast do Juniper trees and bushes grow?
Juniper trees and bushes are slow growers. Many juniper varieties can take between 20 and 50 years to grow to their mature size.
Junipers are coniferous plants that don’t have true flowers. Junipers produce small flowering bracts that eventually become fruit cones. Many junipers are dioecious, which means that each plant is either male or female. Male junipers produce small yellow flowers in the spring to attract pollinators, who then carry the pollen to female plants.
Usage for Juniper Berries
Juniper berries are actually fruit cones with fleshy outer skin. Juniper berries are used to make alcoholic spirits such as jenever or Dutch gin. This is done by fermenting the berries in water before distilling them, which produces a wine-like substance. Dried juniper berries are also used to add flavour to gin. Juniper berries can also be steamed and used as an essential oil.
- How much light do juniper plants need?
Juniper plants need either full sun or partial shade. Juniper should get approximately six hours of sunlight during the day.
- What is special about juniper plants?
Juniper plants are special because of their “berries”, which are actually fleshy cone-like fruits. These berries are used to create alcoholic spirits, infuse gin, and distilled to make essential oils.
- Are juniper plants good indoor plants?
When grown as bonsai, junipers are good indoor plants. Junipers are easy to prune into aesthetically pleasing shapes for bonsai.
- Can juniper plants survive in low light?
Juniper plants will struggle in low-light conditions. These coniferous evergreens need lots of sunlight and will suffer from stunted growth in full shade.
- Why don’t juniper plants grow?
Juniper plants may not grow if not given enough sunlight. Junipers require around six hours of direct sunlight wherever possible. Junipers may also struggle to grow if they are left in waterlogged soil.
Junipers are hardy evergreens that make excellent ornamental trees and shrubs. Juniper plants thrive in containers and most types of well-draining soil. Junipers require full sun or partial shade, ideally with six hours of direct sunlight every day. Juniper shrubs and trees are extremely drought-tolerant and can cope without additional watering.