How to Grow Juniper

Junipers offer year round colour, wildlife benefits and berries for your gin. As a bonus, they're very easy to grow. Choose from columnar varieties that form slim trees or prostrate junipers, which spread horizontally to create excellent ground cover. These drought-resistant plants are perfect for low-maintenance gardens.

Junipers are a group of coniferous shrubs and trees with foliage in shades of green, blue or gold. Common juniper (Juniperus communis) is one of three conifers native to the UK (the other two are Scots pine and yew), though its population is declining. Other popular Juniperus species include Juniperus chinensis (Chinese juniper), Juniperus horizontalis (creeping juniper) and Juniperus squamata (flaky juniper).

Junipers produce male and female cones on separate plants. Female cones take two years to ripen and, once mature, look like blue-black berries. These are the juniper "berries" used in gin making and for culinary and medicinal purposes. If you want to harvest juniper berries, then you need to plant Juniperus communis (common juniper), as berries from other species can be toxic.

Junipers are slow-growing plants that are suitable for topiary and hedging. Juniperus chinensis is commonly used for bonsai. Pencil-shaped varieties like Juniperus 'Blue Arrow' work well in symmetrical displays, for example, on either side of a doorway or gateway. Spreading varieties make excellent ground cover and can help prevent erosion when planted on steep slopes.

 

Where to plant Juniperus

Junipers need free-draining soil, and while they prefer slightly acidic conditions, they also grow well in neutral and slightly alkaline soils. You can plant a juniper shrub in chalky or sandy soils, and many varieties grow well in places with thin soils like rockeries.

Junipers need sun to thrive, so it's best to avoid planting them in full shade, though light shade is fine. You can grow smaller varieties, such as Juniperus 'Compressa' and Juniperus 'Nana' in pots.

 

When to plant Juniperus

It's best to plant a juniper shrub or tree in spring or autumn, when the soil is warm and the weather is neither too hot nor too cold. You can also plant them during a mild spell in winter. If you need to plant a juniper tree in the summer, you'll need to check and water it regularly.

 

How to plant Juniperus

Before planting, give your juniper plant a good drink and let it soak for about an hour. Dig over the planting area to loosen the soil, then dig a hole twice the width of the plant's rootball. Remove the juniper plant from its pot and gently loosen the roots. Place it in the hole, ensuring the soil is at the same level as it was in the pot, and backfill.

Juniper trees tend to be slender, so if you're planting a juniper hedge, check how wide the variety you've chosen grows to determine the correct spacing.

If you're growing juniper in a pot, add some stones or pottery shards to the base of the pot to ensure good drainage. It's also worth mixing some grit in with the compost to help with drainage. You don't need to use an ericaceous compost for junipers – a standard mix like RocketGro Peat-Free Tree & Shrub compost is fine.

 

How to take care of juniper plants

Water new plants well after planting and during dry spells for the first couple of years. Once junipers are established, they don't require feeding or watering, though it's worth adding a layer of mulch around the plant in spring to suppress weeds. Junipers in pots will benefit from an annual application of slow-release fertiliser in spring.

Junipers don't require pruning unless you're creating a topiary display. If you do want to prune your juniper, make sure you don't cut back too far as it won't regrow from dead wood.

 

How to propagate juniper trees and shrubs

It's possible, though difficult, to propagate juniper from the seeds inside juniper berries. An easier method is to take cuttings from established plants. 

How to grow juniper from cuttings

The best way to propagate juniper is by taking cuttings. Although the usual process for propagating conifers is to take semi-ripe cuttings in early autumn, a detailed study by the Forestry Commission found that hardwood cuttings taken in February and March had a much better survival rate.

The recommended approach is to take 10 cm cuttings from the tips of branches and insert these into a mix of peat, bark and perlite. Place the cuttings in a humid environment, for example by placing a plastic bag over the cuttings and leaving them in a sunny spot. Keep the cuttings in this environment for 12 weeks, then gradually harden them off to greenhouse conditions over another 12 weeks. Pot up the seedlings in October and leave them to grow in pots for a year before planting out.

How to grow juniper from seed

Growing juniper from seed is a slow process, and it can be tricky to get seeds to germinate. To give yourself the best chance, use cleaned seeds taken from juniper berries rather than planting berries directly. There are a couple of different methods you can use. One method is to mix the seeds with damp sand or a sand/compost mix and place in a bag in a fridge at 4 C for at least seven months and up to a year. Then sow the seeds and wait, as germination can take up to a year.

Alternatively, you can just plant the seeds outside in autumn and see what happens. It may be that you get seedlings popping up several years after planting!

 

Common problems

Juniper can be affected by fungal infections, particularly Phytophthora austrocedri, which damages the roots of a plant and eventually kills it. Affected plants must be dug up and destroyed. There's no magic solution to preventing root rot, but ensuring junipers are planted in free-draining soil that isn't prone to waterlogging will help.

Honey fungus can also affect juniper trees and shrubs. If you suspect a plant is affected, peel away a section of bark near the base and look for a thin white layer that smells like mushrooms. As with phytophthora, the only control for honey fungus is to destroy affected plants and try to limit the spread.

Juniper scale insects are mostly harmless, but large infestations can cause foliage to turn yellow and die back. Brown patches on conifers are more commonly caused by cypress aphids, honey fungus or root rot.

If you notice cankers developing along with spidery orange jelly-like growths, this is a symptom of pear rust. Remove any affected stems.

 

Our favourite varieties of juniper

Juniperus squamata 'Blue Star' is a dwarf conifer with striking silver-blue foliage. It forms a compact, low mound and looks good in rockeries, pots or at the front of beds and borders.

Juniperus procumbens 'Nana' is a spreading variety that forms a mat over the ground. It has tiny, spiky blue-green leaves that give the impression of a lush carpet. Plant it in low-maintenance gardens, rockeries and gravel gardens.

Juniperus communis 'Compressa' is a compact, upright cultivar of the native Juniperus communis. It grows slowly, reaching a maximum height of around 80 cm, and has dense green needles. A good choice for rock gardens and other dry gardens.

Juniperus scopulorum 'Blue Arrow' (Rocky Mountain juniper) has gorgeous steel-blue foliage and a narrow, symmetrical shape that suits formal planting schemes. This upright, columnar juniper grows to around 2.5 m.

Juniperus 'Pfitzeriana Aurea' has arching branches with golden-green scale-like leaves. It grows up to a metre tall and spreads to around 2.5 m. It works well as a low hedge or simply left to sprawl as ground cover. 

 

FAQ

Can junipers grow in pots?

Compact juniper trees and shrubs grow well in pots. Make sure your pot has good drainage and include some grit in your potting mix. Look for a dwarf juniper such as Juniperus 'Compressa' or Juniperus 'Gold Cone'.

Can junipers grow in shade?

Junipers need sun to thrive and are best planted in full sun or light shade. Yew is a better choice if you want a conifer for shade – you can buy compact varieties as well as hedging plants.

Can you grow juniper from berries?

You can grow juniper from berries, but you need a lot of patience, and results aren't guaranteed. Removing the seeds from the berries and cleaning them gives you a better chance of germination, and the seeds need a long, cool period before sowing. It's much easier to save yourself the time and effort and just buy a juniper plant!

Can you grow juniper from cuttings?

You can grow junipers from cuttings. Although many people suggest taking semi-ripe cuttings in autumn, a Forestry Commission study found that hardwood cuttings taken in February and March had better success rates.