With their fabulously fragrant scent and beautiful blue berries, junipers are beloved by horticulturalists. Although they are fairly hardy and easy to care for, junipers have some quirks that you should be aware of when it comes to pruning.
So how do you prune or trim a juniper bush? That’s exactly what we’re going to cover in this article.
What are juniper bushes?
Juniper is a versatile evergreen member of the Cypress family. Depending on the conditions, junipers will grow as either broad, low shrubs or as trees. The latter can reach up to 10 meters high. Junipers are available in a broad swathe of over 60 varieties, with the Common Juniper (Juniperus communis)
being the most well-known.
Juniper bushes are native to a wide variety of countries including America, Europe, parts of Africa, the Middle East, and northern Asia. They are tough, adaptable plants that can thrive in various growing environments. Junipers have needle-shaped leaves and vibrant blue berries with tough skins.
Junipers can be grown
in a variety of ways. Some junipers, like Juniperus chinensis
, grow as tall trees. Other varieties, such as Juniperus horizontalis
, are low-growing ground-cover shrubs. Juniper plants can even be grown as bonsai. The techniques covered in this guide are suitable for all types of junipers.
Why prune juniper bushes?
Juniper trees are hardy evergreens that can grow quite happily on their own. But pruning can still yield a lot of benefits.
Junipers will still accumulate dead and diseased branches. Pests such as aphids or juniper scale can afflict branches, so affected areas must be trimmed. Getting rid of dead branches also helps to encourage fresh growth.
Like many shrubs, junipers can also be trained into desired shapes by gardeners. This is most effective when the plant is relatively young.
To read more about trimming plants, visit our trimming page.
Benefits of trimming juniper trees
Although junipers don’t naturally require pruning, trimming them back does create several benefits.
Junipers are slow-growing plants, taking as long as 50 years to reach their mature size. But trimming juniper plants can encourage fresh new growth. Cutting branches back to fresh buds stimulates the plant, causing it to produce bushy growth.
As junipers mature, their branches can die or become infected with pests and diseases. Removing these affected branches protects the rest of the juniper tree and stops the problem from spreading.
Risks of trimming juniper trees
Although pruning junipers does yield some benefits, there are risks if trimming is not performed properly. Stunted growth is the main risk.
As some junipers mature, the young needle-like foliage gradually flattens and becomes scaly. These mature branches can no longer produce fresh growth. Trimming a juniper to leave only these scaly branches prevents the tree from growing.
When to trim juniper bushes
The best time to trim a juniper bush is before the new growing season begins near the start of spring, especially if you’re looking to sculpt the tree to your liking. This should be done once a year while the tree is young.
The best time to trim away dead branches or ones infected by disease is towards the end of winter or in early spring. This helps to redirect the juniper’s energy to boost fresh growth. If necessary, you can also trim these kinds of branches throughout the year.
Cutting back juniper plants
Can I cut back my juniper plant?
Although it isn’t technically required, you can cut back a juniper plant. Cutting back a juniper shrub or tree can help remove dead or diseased foliage. Cutting branches back to young buds can also promote vigorous new growth.
How much should you cut back?
While you can cut back a juniper, don’t cut too much back in one go. Removing too many branches can cause stunted growth and may even harm the plant. A good rule of thumb is to never cut back more than 25% of the juniper plant in one go.
Best season to prune a juniper tree?
Late winter or early spring is the best season for pruning juniper trees. Juniper plants go dormant over the winter, which makes it easier to prune them. Prune dead or diseased branches in the winter then focus on pruning to a desired shape in the spring.
How do you shape a juniper plant?
Juniper plants can be shaped easily by gardeners. This makes juniper trees ideal as hedges or topiary pieces.
Begin by trimming away tips of the branches to create an even length around the juniper. You can start shaping the tree here – pyramids or balls are popular topiary shapes. Step back from the plant often to assess your progress. This prevents you from trimming too much at once and creating a messy shape.
Never cut off more than a quarter of the juniper in one go, otherwise you could harm the tree.
Tools for trimming juniper bushes
To prune a juniper bush properly, the right tools are required. Here’s a list of the tools needed for trimming juniper bushes:
- Hand shears – Hand-held clippers or shears will make short work of thin branches and suit the light pruning that junipers need.
- Lopping shears – Stronger lopping shears with longer handles are useful for pruning thicker juniper branches.
- Pruning saws – For really thick juniper branches, use pruning saws.
- Pruning tool disinfectant – When trimming away diseased branches, you don’t want to contaminate any healthy branches that you might prune afterward, it’s vital to disinfect your pruning tools immediately.
How to trim juniper bushes
Now that we’re familiar with the tools required, let’s cover how to trim a juniper bush:
- Begin by assessing the juniper, scouting out any dead branches or any parts showing signs of disease.
- Use your pruning tools to trim off these branches. Keep pruning light and don’t get overzealous. Always cut your chosen branches close back to the trunk. For low-growing juniper shrubs, this should be sufficient pruning.
- For juniper trees, use the three-cut technique. Start by making your first cut about a third of the way down the branch.
- Make your second cut a few inches further along.
- Then remove the branch right up to the branch collar – the area where the branch begins to move horizontally away from the trunk.
Training a juniper plant
What is training a plant?
Training a plant is the act of cultivating it to grow in a specific way. This involves selectively trimming the plant into a desired shape until it grows exactly how you want. Junipers are commonly trained for bonsai.
How to train a juniper plant
Junipers are one of the easiest trees to train, especially for bonsai. The exact training method depends on the shape that you want.
To create a pyramid-shaped juniper, it’s best to train the tree to grow narrow and upright. In the early spring, remove branches that are starting to pull away from the desired shape. Perform training like this every spring to maintain the pyramid.
Training works best when performed with younger juniper plants.
What not to do when pruning juniper bushes
The main thing to avoid when pruning juniper bushes and trees is to be careful of the “dead zone”
. The older and larger a juniper plant grows, the less sunlight that its interior receives. This creates an area of the shrub that cannot support new growth.
If you trim too aggressively and cut into the dead zone, the juniper won’t be able to regrow the lost branches. This will leave you with a noticeable gap in the shrub. Always keep pruning light when trimming healthy branches.
Pinching vs Pruning
What is pinching?
Pinching is a pruning method that involves removing the main growing tip of a branch. Branches should be pinched above one or two leaf nodes. This allows the plant to continue growing. Pinching helps create bushier, fuller growth.
Should I pinch junipers?
Junipers are slow-growing plants, so pinching is not recommended. Pinching young buds can stunt the growth of a juniper. It’s better to prune branches back to the desired length once they’ve had a chance to grow.
While junipers don’t really require pruning, it can be of great benefit. Pruning can promote a healthier, more vigorous tree. Pruning and trimming allows gardeners to shape juniper plants into desired forms for bonsai or topiary.