Juniper: growing, pruning & harvesting juniper berries

Juniper is a versatile plant with plenty of uses: in the kitchen, in gin-making, in the garden as a hedge or even as a decorative bonsai.

Juniper (Juniperus) is a decorative woody plant that has a unique look, aroma and healing properties. Here you will find out how to plant and care for juniper plants and why juniper berries are technically not berries at all.

Juniper: blooms, leaves and other characteristics

The juniper genus (Juniperus) belongs to the cypress family (Cupressaceae). The genus contains about 80 species, of which only two occur naturally in Central Europe. The other juniper varieties are almost all distributed throughout the Northern Hemisphere – from the Arctic to tropical regions. Evergreen juniper trees or juniper bushes grow upright, creeping or horizontally and give off a strong fragrance. Their leaves are needle-shaped or scaled, often soft and slightly flattened, but sometimes very pointed. Juniper flowers are often white or pink, very small and inconspicuous. Juniper is better known for its cone fruits, which are often called berries. Until the female cones have reached their blue colour, they have to ripen for up to two years. Juniper is dioecious, which means separate male and female juniper plants are needed for fertilisation.

But how big does juniper grow? Size varies greatly from species to species and ranges from a one metre tall shrub to a ten metre tall juniper tree. The common juniper (Juniperus communis), which is often planted in milder European climates, reaches an average height of about five to eight metres. 

As well as being used as ornamental plants, juniper fruits are used to make gin, essential oils and condiments. They are also high in antioxidants and anti-inflammatory in nature – juniper berries are often used as a natural remedy to treat bronchitis.

Tip: Juniper is a traditional grave decoration, as their evergreen foliage and spire-like growth was thought to represent eternal life.

How to plant junipers: the right location and method

The Juniperus genus is very undemanding and robust, which is why you can plant any juniper in just about any location.

Only shade should be avoided: junipers need a lot of light to thrive. A place in the sun is ideal, while partial shade is tolerated too. Juniper is not overly sensitive to drought and even chalky soil is no problem for this hardy plant. Make sure the soil is well draining, though the juniper will also tolerate a location that is occasionally moist.

Tip: If you want to harvest juniper berries, plant one female and one male juniper plant.

Spring is the best time for planting junipers, but it is also possible to plant in early autumn. Spacing between juniper and other plants depends on the species and its growth characteristics. Place the root ball of the juniper in a bucket of water to soak. Then dig a planting hole in the desired location that is about twice the size of the root ball. If your garden soil is very heavy, you should dig the hole deeper. Mix the dug up soil with plenty of sand to improve water drainage. Then place the juniper in the hole, fill with soil and press down. Make sure to water the freshly planted juniper well.

Potted juniper: You can also keep some small junipers in pots and place them on your patio or balcony. Juniperus communis ‘Compressa’ or Juniperus squamata ‘Blue Star’, for example, are suitable for this. Add a drainage layer of clay shards to the bottom of the pot to ensure good drainage. High-quality potting soil, such as our Plantura Organic All Purpose Compost, is perfect for potted juniper.

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Tip: Junipers can be used to form an excellent hedge. To do this, reduce the plant spacing and place two juniper plants per metre of hedge. The columnar juniper Juniperus scopulorum, is one variety suitable for this job.

How to care for junipers: the right location and method

There is not a huge amount to consider when caring for junipers. Although the plants grow slowly, they do not require any additional care. Only young junipers require watering and, depending on the time of planting, winter protection can be helpful.

Juniper care: watering and fertilising

Since junipers cope well with drought, there is no need to water larger, well-established plants. However, you should water freshly planted, young junipers regularly to support healthy growth. In the first few years however, watering is only really necessary when it is dry. Likewise, junipers do not usually require fertiliser, given they are planted in a suitable location. Nonetheless, in sandy soils or in pots, apply a little slow-release fertiliser occasionally. Junipers need a nutrient balance that is low phosphorus and high in magnesium. Because of these special requirements, our Plantura Rose Food is actually ideal for junipers. You should also be sure to repot your potted junipers every so often, as fresh soil stimulates healthy growth.

How to prune juniper

Juniper tolerates pruning well, which is why it is often used in topiary. Bear in mind, however, that juniper grows slowly and takes longer for new shoots to form. Although it is not strictly necessary to prune junipers, it does encourage branching. When pruning, avoid cutting into the old wood: After heavy pruning, older junipers barely produce any new shoots. A large, healthy plant can be pruned back a little more. Although, it is not guaranteed to regrow. To avoid this risk, simply remove visible dead branches in spring and regularly prune back young junipers slightly. Since juniper needles are very sharp, always wear gloves when pruning.

Common juniper pests and diseases

Although juniper is very robust, there are still some pests and diseases that plague the sturdy plant.

• Phomophis blight (Phomopsis juniperivora): Also known as conifers dieback, this disease results in brown discoloured needles and small black fruiting bodies of the veru fungus that causes the disease. To treat, cut all affected parts of the plant back extensively.

• Juniper ermine moth (Argyresthia trifasciata): If the shoots turn brown from the tips, you may have an ermine moth infestation on your hands. You should seek advice from a plant protection service on how to best combat this for your individual plant.

• Rust fungi (Gymnosporangium): Hawthorn rust, pear rust or juniper rust are caused by various rust fungi. You can recognise them from their yellow, tongue-shaped fruiting bodies and swollen shoots. Cut off any infested parts of the plant and dispose of them in your household waste. These fungi can spread to other plants, such as pear trees.

Juniper propagation

The best way to propagate junipers is from cuttings. To do this, take a young shoot from the main shoot in late summer. This should be slightly woody, but still green at the base. Cut off the stem bark with a sharp knife and remove the tip of the shoot and the lower needles. Then plant the cutting into a mixture of all purpose soil and sand and place the whole thing in a bright place with high humidity at around 20°C. Keep the soil moist at all times. By spring, roots should have formed and the juniper is ready to be repotted or transplanted outdoors.

Tip: When propagating, be sure to use a cutting from the juniper’s main shoot because the conifer shoots will “remember” their growth direction. A side shoot, on the other hand, will not grow straight up after propagation.

Are junipers winter-hardy?

A well-established juniper does not need any extra protection in winter. Though young plants should be protected with a layer of mulch. For potted juniper, place it on a wooden block and wrap it with some jute or a hessian sack to be safe.

Harvesting and using juniper berries

Of all the varieties, common juniper (Juniperus communis) is the one most commonly used in the kitchen. The cone berries of the female juniper are ripe as soon as they turn dark blue. This happens two years after pollination. The berries are used, among other things, in juniper tea or for making gin. Other species, such as the savin juniper (Juniperus sabina), are poisonous in all parts. Juniper wood contains essential oils and are also often used to flavour meat.

Tip: Savin juniper was also used in the past for medicinal purposes. It was used, among other things, to clean wounds, for respiratory problems and abortion.

Are juniper berries poisonous?

Juniper species are slightly poisonous in some, sometimes in all, parts of the plant. While common juniper berries were used in the past for medicinal purposes, they also contain substances which, in excess, can cause irritation in the gastrointestinal tract or on the skin. Juniper should not be consumed during pregnancy or if you have kidney problems. Excessive juniper consumption is also poisonous for pets. Savin juniper is even classified as poisonous and can cause severe irritation and skin blistering from skin contact alone. Vomiting, diarrhea, and blister pain are among the most common symptoms of savin poisoning.

Juniper and heather shrubs are happy to share the same sunny, dry and sandy locations. And like juniper, the type of heather “cross-leaved heath” is very popular in gardens too. Learn all about how to care for it in our article on cross-leaved heath.