Planting buxus: tips for growing, fertilising & care
Hardly any other evergreen plant is as popular as the box tree. This is our guide to box tree care, including info on diseases, pests and varieties.
Box trees (Buxus) or box hedge plants hold a special place in the hearts of many gardeners and garden enthusiasts. They have become inseparable from garden landscapes. These evergreen plants decorate gardens and parks as hedging or screening plants, or sometimes (because they can be pruned and formed easily) in the shapes of various animals. However, there are a few tips to follow for your box tree to thrive. Keep on reading to learn everything from planting and care to propagation and overwintering of the evergreen shrub.
Contents
Box tree: origin and characteristics
The name of the box tree is derived from the Latin term ‘buxus’ and the Ancient Greek word ‘púxos’. In Ancient Greece, many objects were even made from the wood of box trees. The box tree family (Buxaceae) consists of 70 species worldwide.
Most of the time box hedge plants are (as the name suggests) grown as shrub or hedge but can also grow as a tree. The leaves are evergreen, dark green and leathery. Demands on location are fortunately quite little and box trees are generally low maintenance. They cope well with frequent cutting. However, the evergreen bush grows quite slow, only 10 to 20 centimetres in a year.
Buying box trees
When buying your box tree, make sure the plant looks healthy and well-kept. Look out for any signs of disease or pests on the box tree. Also, foliage should be rich and green. Don’t forget to check the roots.
Box trees can be bought in garden centres, hardware stores or tree nurseries. Many online retailers also offer box trees that can be shipped and delivered right to your door.
Box tree species and varieties
These two types of boxwood (Buxus) are many gardeners’ favourites: Buxus sempervirens and Buxus microphylla. Buxus sempervirens is the common box tree which is native to the Mediterranean region. Buxus microphylla, the Japanese or small leaf box tree, originates from Korea and has been cultivated in Japan for centuries. In the following, we will introduce you to popular varieties of these two species.
Buxus sempervirens:
- ‘Suffruticosa’: The variety best suited for bordering flower beds or establishing edges. It forms long, medium sized, light green leaves and is usually not taller than 50 cm.
- ‘Blauer Heinz’: This variety is also suitable for borders as it is low-growing and frost-resistant. The leaves have a slight blue hue to them.
- ‘Aurea Pendula’: This boxwood variety is interesting because of its special leaf colouring. After sprouting, the leaves are golden yellow and later turn green.
- ‘Globosa’: If you want a box tree shaped like a ball, this variety might be the one; it grows slightly rounded naturally.
Buxus microphylla:
- ‘Faulkner’: A popular variety of the Buxus microphylla. It has shiny olive leaves and is very resistant to drought and cold. Faulkner bush trees grow very bushy and are therefore well suited as ground covers.
- ‘Herrenhausen’: Another favourite boxwood variety. This variety is especially suitable as a hedge or bed border; it is rather small and resistant to fungal infestations.
Planting box trees: location and instructions
Box trees are content in many locations, but to create ideal conditions for growth consider the following. The ideal location for box trees is sunny and warm. Box trees like locations with morning and evening sun. The full midday sun, on the other hand, is not their favourite. Make sure the soil is loose and airy. Avoid waterlogging by working sand into soils that are too heavy. Slightly damp, alkaline soils with a pH value between 6.5 and 7.5 offer ideal conditions for box tree growth.
The best location for planting a box tree:
- Sunny to semi-shady location
- Loose and airy soil
- Soil rich in humus
- pH value between 6.5 and 7.5
It is best to plant box trees in spring between March and May. To plant the shrub, dig a sufficiently large planting hole. Now place the box tree in the middle of the hole, then fill it up with the excavated soil, preferably enriched with compost and water it well. When planting buxus as a hedge, make a ditch and plant the box trees with a distance of 20 centimetres for low hedges and 30 to 35 centimetres for taller hedges.
- Perfect for all flowering plants in garden beds & pots
- For beautiful blossoms & healthy plant growth
- Peat-free & organic soil: CO2-saving composition
A step by step guide to planting a box tree:
- Dig out a hole for planting (box hedge spacing should be at least 20cm for low 30 to 35 cm for tall hedges)
- Place the box tree in the middle of the planting hole
- Fill it with excavated soil and compost
- Water the plant
Re-planting box trees
You can transplant box trees – even when they are very old. Choose a day that is frost-free but not too hot. To dig out the box tree, use a spade to dig out the root ball (in a circle as wide as the crown of the box tree). The depth depends on the size of the tree – at least 40 centimetres for a small bush and at least 60 centimetres for a large bush. Use a digging fork to loosen the ground under the bush as much as possible. Then lift out the box tree and cut back any damaged roots. Afterwards, leave the excavated box tree to sit in some water in a pot for half an hour. It can then be planted at its new location or in a flower pot, as described above.
Propagating box trees
There are two vegetative methods suitable for the propagation of box trees: propagation by cuttings or by division. We will introduce you to both in the following.
Propagating box trees with cuttings
The best time for propagation by cuttings is late summer or autumn. Use older branched shoots from strong, bushy plants. They are the most suitable, but young plants can also be used for cuttings. One-year-old shoots are the best candidates for this method.
Summary:
- Tear off biennial shoots about 15 centimetres long against the direction of growth (with a movement downwards)
- Shorten shoot tips by a third
- Remove leaves from the lower third of the newly cut off branch
- Cut off protruding bark
- Plant in pots with cuttings up to the leaf base
- Water thoroughly and keep watering to maintain moisture
- Let the cuttings grow in room temperatures
- Plant outside the following year
Dividing box trees
With this method, you cut your box and divide it into two parts. However, this method is not without risk as the cuts make possible openings that allow diseases or pests to settle more easily. This method is clearly inferior to the easier way of multiplying box trees by cuttings.
Summary:
- Dig out the plant generously around the root ball (with a radius at least the current height of the tree)
- Split the tree on a hard surface with a spade or saw
- Newly created plant should have at least two shoots
- Plant outdoors or in a pot
Maintaining box trees
Although box tree is generally easy to care for, it needs to be watered and fertilised sufficiently. Continue reading to find out about proper watering and fertilising care as well as pruning and overwintering.
Watering box trees
Since box trees have shallow roots, it cannot draw water from deeper layers of soil. Therefore, it is dependent on regular watering during dry periods. With potted plants, you should take special care that the soil does not dry out – even in winter. If you find brownish leaves and shoots on the plant after winter, this can be a sign of drought during the cold season. In hot and dry summers, spray the box tree with a hose or watering can to remove dust from the leaves.
Fertilising box trees
Typical symptoms for nitrogen deficiency are reduced growth and yellowish discoloration of the leaves. To prevent this from happening regular fertilisation is necessary. The best time to fertilise is from spring to early summer. We recommend not fertilising later in the year, as shoots promoted by the fertiliser die off quickly during frost. For box trees, use a fertiliser that offers a long-term organic effect- such as compost combined with Plantura All Purpose Plant Food. An organic slow-release fertiliser provides the plants with nutrients over the long term and at the same time promotes healthy soil life and production of hummus.
- Perfect for a variety of plants in the garden & on the balcony
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Pruning box trees
Pruning plays an important role in box tree care: it promotes growth, the bushes become more dense and lush. Moreover, cutting the box tree allows you to shape it. You can prune between April and September. Importantly, choose a day with mild weather for pruning – not too sunny and without rain. Both hand scissors and electric scissors are suitable for pruning, just make sure they are sharp. You might want to use stencils to help you with the shape.
Overwintering box trees
Box trees usually survive winters alright whether in garden beds or hedges. However, box trees in pots are more sensitive to the cold and require some measures to be taken in order to not freeze to death. If the potted box tree is not too heavy, simply move it into a protected place for winter (for example next to a house wall). It is also important to protect the pot and box tree from below, so placing a wooden plank underneath it is a good idea. If the pot is too large or too heavy to be moved, you can protect the plant by using jute bags. On very cold days and nights, wrap the box tree itself in a jute bag ‘blanket’. Also remember to regularly water your box tree in winter – but only on frost-free days to avoid frost damage on the roots.
Box tree diseases
There are several diseases that can have a negative impact on box trees and some of them, unfortunately, can lead to severe consequences. We will give you a short overview of the most important box tree diseases.
Volutella blight
Volutella buxi fungus penetrates the plant through its bark, which may cause shoots to die. If your box tree is affected by Volutella buxi, cut back and remove the diseased parts.
Boxwood blight or boxwood leafdrop
Triggered by the fungus Cylindrocladium buxicola, boxwood leafdrop, as the name suggests, causes entire box trees to lose their leaves and atrophy. The first signs of infestation are brownish or orange spots on the leaves, which expand as the disease progresses. Finally, the bush discards all its leaves and the shoots become bare. With severe infestations, the only thing that helps is to remove the affected plants; alternatively, a fungicide can help.
Boxwood rust
Another disease caused by fungi is boxwood rust. Rust fungi usually stain the leaves of a plant from rust red to brown. The affected parts of the plant can simply be cut off and disposed of.
Box tree pests
The most infamous pest of buxus is definitely the box tree moth. However, there are also other organisms that like to munch on the evergreen shrub. This is our brief overview of the most common box tree pests.
Box tree moth
The box tree moth (Cydalima perspectalis) is a newly introduced pest in Europe that has been causing a significant amount of damage to European box trees in recent years. This species is active from the middle of May until September. The box moth caterpillars completely defoliate the evergreen shrubs at this time. Learn everything about the box tree moth in this article.
Tip: With a pheromone trap such as the Plantura Box Moth Trap, you can easily detect a box moth infestation at an early stage. This allows you to react quickly and control the pest.
- Reusable pheromone trap for monitoring box tree moth activity
- For the early detection of infestations - covers an area of up to 180m2
- 100% insecticide-free - not harmful to humans or pets
White mites
Twisted shoots and leaves are caused by mites. Although they do not harm the box tree, the aesthetic of the buxus suffers. If you discover infested parts of the plant, just remove them to stop the mites from spreading.
Boxwood psyllid
Boxwood psyllid also preys on buxus foliage. You can recognize an infestation by the spoon-shaped curved leaves. To get rid of the infestation it is best to cut back the affected leaves.
Box tree: is it toxic to humans and animals?
It is safe for box tree moths and other box pests to feed on buxus. For everyone else, however, the evergreen bush is highly poisonous due to 70 different alkaloids in the roots and leaves of the plant. However, the taste is quite bitter making it very unlikely that anybody would eat boxwood in large quantities. Be careful with children though, because even a small amount of the poison can lead to terrible consequences for those with a low body mass. Therefore, supervise small children in the garden and teach them not to eat the plant at an early age. What is more, be careful with pets (especially rodents) around the box tree. If you take those precautions, you can grow the evergreen bush without worries.
