March 5, 2025 Peter van Dijk

Pruning Boxwood

The Buxus Sempervirens is a popular garden plant that is often used as a hedge or for topiary. This evergreen plant is loved for its compact growth and versatility in the garden. To keep the Buxus healthy and beautiful, it is important to prune it regularly. In this blog, we discuss when and how best to prune a boxwood, as well as post-pruning care and dealing with problems such as the boxwood moth.

When to prune boxwood?

The best time to prune a boxwood is twice a year, namely in the spring and in the summer.

Pruning Boxwood in the Spring (April - May)
The first pruning takes place in April or May, when the frost period is over and the boxwood begins to grow. This ensures compact and full growth throughout the year. It is important not to prune too early, as late night frosts can damage the freshly pruned plant. Use sharp and clean pruning shears to make a neat and healthy cut. This promotes even growth and prevents diseases.

Pruning Boxwood in the Summer (August - September)
The second pruning is ideally carried out in August or September. This keeps the boxwood in a neat shape and gives it sufficient time to recover before winter. Do not prune too late in the season, as young shoots may otherwise be vulnerable to frost. For a neat shape, it is recommended to use a pruning template or a tension wire, especially for hedges and shapes such as spheres or pyramids. Avoid pruning in bright sunlight to prevent leaf burn. A cloudy day or a time in the early morning or late afternoon is ideal.

How to Prune Boxwood?

To keep your boxwood healthy and beautiful, a correct pruning method is essential. Follow these steps for the best result:

Use sharp tools such as hedge shears or pruning shears to ensure a clean and neat trim. Blunt blades can damage the branches and cause ragged edges, making the boxwood more susceptible to diseases.
Start with a light trim to avoid removing too much. Work in small steps and check the shape of the plant in between.
Maintain a straight line when pruning hedges. If necessary, use a string or slat as a guide to achieve a straight hedge. Always work from top to bottom and ensure an even distribution of the pruning.
Do not prune in full sun, especially on warm days, to avoid leaf burn. The pruned leaves can dry out due to the intense sun and show brown spots. The best times to prune are early in the morning or later in the day during cloudy weather.
After pruning, provide water and nutrients to promote the plant's recovery. An organic fertilizer specifically for boxwood helps the plant quickly regain strength and stimulate new growth.

Pruning boxwood with an electric hedge trimmer

An electric hedge trimmer is ideal for pruning large boxwood hedges. To achieve a neat result, keep the following tips in mind: Ensure the blades are sharp to make a clean cut. Regular sharpening prevents ragged cuts that can weaken the hedge. Move the hedge trimmer evenly over the hedge and work from top to bottom. This prevents uneven sections and keeps the hedge symmetrical. Check periodically to ensure the hedge remains straight and even. Step back a few steps occasionally to assess the whole and correct if necessary.

Pruning Boxwood

For smaller boxwood shapes or decorative shapes such as spheres and cones, a manual pruning shears is a better choice. With sharp hand shears, you can work more precisely and preserve the delicate shapes without damaging the plant.

Preferably use a shaping template or stencil to achieve a symmetrical result for boxwood spheres or figures.
Work with small, gradual cutting movements and rotate regularly to view the boxwood from different angles.
For an extra clean finish, you can lightly touch up the shape afterwards with a fine pruning shears.

By pruning regularly and carefully, your boxwood remains healthy, full, and beautifully shaped.

Can I prune a boxwood back completely?

Yes, a boxwood can be pruned back completely, but this must be done carefully. This is often called ‘rejuvenation pruning’ and is best done in early spring. Please note that recovery can take several months to a year before the plant fully sprouts again. Ensure that the boxwood receives sufficient water and nutrients after pruning to stimulate growth. It is also important to keep a close eye on the plant and protect it against diseases and pests, as a pruned boxwood can be more vulnerable.

Boxwood Shape Pruning

Boxwood is perfect for shape pruning and can be trimmed into all kinds of geometric or playful shapes, such as spheres, cones, pyramids, or even artistic forms. The best time for shape pruning is in the spring, when the plant starts growing again, and again in late summer to maintain the tight shape. During pruning, it is important to work carefully and evenly to preserve the symmetry of the shape. By pruning regularly, the boxwood remains compact and dense, which enhances the desired sleek and neat appearance.

When to prune boxwood with box tree moth?

If your boxwood is affected by the box tree moth, it is important to prune the plant immediately as soon as you notice the caterpillars or damage, usually in the spring or summer. Carefully remove the affected parts of the plant to prevent further spread of the caterpillars. After pruning, you can treat the plant with biological or chemical agents against the box tree moth to keep the infestation under control. It is also advisable to repeat the pruning work regularly so that you keep the boxwood healthy and the moth does not get the chance to spread again.

What if I don't prune my boxwood?

A boxwood that is not pruned grows haphazardly and can lose its dense structure. This can lead to bare spots, a less attractive shape, and a weakened plant. Without regular pruning, the boxwood also allows less light and air to pass through, which increases the risk of fungi and other diseases. Additionally, it can cause an increased risk of pests such as the boxwood moth, which can spread more quickly in an unpruned shrub. To keep your boxwood healthy and maintain its shape, it is therefore important to prune regularly.

Why does my boxwood turn yellow after pruning?

Yellow leaves after pruning can have several causes:

Pruning in bright Sunlight: When you prune a boxwood during intense sunshine, this can lead to leaf burn. Freshly pruned foliage is more sensitive to the sun, resulting in burnt, yellow leaves. It is therefore better to prune on cloudy days or in the early morning or late afternoon, when the sun is less intense.
Nutrient deficiency: A lack of essential nutrients, especially nitrogen, can lead to yellow leaves. Nitrogen is important for photosynthesis and the overall growth of the plant. If your boxwood turns yellow after pruning, it may be a sign that the plant is not receiving enough nutrition. It is advisable to use a special boxwood fertilizer rich in nitrogen to support the plant.
Pruning too rigorously: When you prune off too much of the plant, this can put the boxwood under stress. Losing too many leaves at once reduces the plant's ability to absorb sufficient nutrients, which can lead to the remaining leaves turning yellow. It is important to prune gradually and not remove more than a third of the plant at once.
Poor soil drainage: When the roots of the boxwood cannot breathe properly due to poor drainage, they can rot or fail to absorb enough water and nutrients. This can lead to yellowing of the leaves, especially after pruning, when the plant is already more vulnerable. Ensure well-draining soil and consider transplanting the plant into a raised bed or one with better drainage if this is a problem.

To help your boxwood recover from the yellowing, give the plant sufficient water, provide a good fertilizer, and ensure proper care so that it regains its healthy green color.

Buxus care after pruning

After pruning, the boxwood needs extra care:

Fertilizing: Use a special boxwood fertilizer to promote growth and help the plant recover of pruning. This ensures better root development and vitality.

Watering: Ensure sufficient moisture, especially in warm weather, so that the plant can recover well and stimulate new growth. However, avoid overwatering, which can cause root rot.

Mulching: A layer of compost or mulch around the base helps keep the soil moist, regulates the temperature of the roots, and protects against weed growth.

Pest control: Regularly inspect for box tree moth and other diseases so that you can intervene quickly and the plant remains healthy. This prevents diseases or pests from spreading further after pruning.

With these tips, your boxwood stays healthy, green, and in top shape all year round!