Box (Buxus) is commonly planted in gardens as a clipped, formal plant or hedge, although there are many types available that are ideal for naturalistic planting. While box has been a traditional stalwart in gardens, it is now proving more difficult to grow well due to disease and pests marring their neat appearance.
Box is tolerant of a wide range of soil types, provided there is adequate drainage and it does not dry out completely. A reliably moist soil is especially important if growing in full sun, otherwise the foliage may scorch. Box will tolerate deep shade and is ideal for planting beneath taller trees.
Planting in the garden
- Box should be planted in autumn or spring
- For hedging prepare a planting area by thoroughly cultivating the soil to a spade's depth and up to 90cm (3ft) wide
- For individual specimens dig a planting hole to a spade's depth and a diameter of three times the width of the rootball
- On poorer soils spread organic matter, such as well rotted manure or garden compost, over the prepared area and fork in. Do not place organic matter in the bottom of a planting trench or hole
- Plant common box, Buxus sempervirens about 30-40cm (1ft-16in) apart
- Compact cultivars, such as B. ‘Suffruticosa’ and Buxus microphylla, can be planted 10-15cm (4-6in) apart
Do not allow young plants to dry out. Check regularly and water to keep the soil moist. Once established, apply a general-purpose fertiliser such as Growmore at 70g per sq m (2oz per sq yd) in spring and mulch to a depth of 5cm (2in).
If well cared for, small plants should form a reasonable hedge or, in the case of B. sempervirens 'Suffruticosa', parterre within three to five years.
Planting in containers
Box can be successfully grown in containers, and is often clipped into formal topiary shapes.
Select a container at least 45cm (18in) in diameter and use a loam-based compost, such as John Innes No 3. Make sure plants never dry out, even in winter.
Apply a general purpose liquid feed monthly during summer. Topdress established container-grown plants in spring with fresh compost and a little slow-release fertiliser, such as Vitax Q4 or blood, fish and bone.
Pruning and training
Cut back young hedge plants and topiary by up to one-third in May to encourage bushy growth. Further trimming can be carried out between May and August, as required.
Trim mature hedges and topiary twice during the summer, with the first cut in about late May and the final cut before the end of August.
Old, neglected plants usually respond well to hard pruning in late spring (May) and can be cut back to within 15-30cm (6in-1ft) of the ground.
Box can be easily propagated by taking semi-ripe cuttings in early to mid-summer as the new growth is beginning to become firm. Cuttings will root in the open ground if the soil is moist and there is some shade. More reliable results come from placing cuttings in a cold frame or similar environment. A heated propagator will speed the rooting process, and you should see roots after eight weeks, as opposed to up to eight months without heat.
Grow on the cuttings, pinching out the tips regularly. In the autumn plant out into a nursery bed, spacing plants 30-45cm (1ft-18in) apart and grow on for three to four years.
Sow seed in autumn or early spring and place in a cold frame. From seed it may take four to five years to obtain transplants. Buxus sempervirens and its cultivars can also be divided in spring using a spade. The resulting plants will be slightly variable in habit - an issue not encountered with cuttings as these will all be identical.
For long-term plantings, consider alternatives to box as the disease box blight and other problems (see section below) can be a considerable issue, making is it almost impossible to grow neat, unaffected hedges.
However, many forms of box are available to gardeners, some viewable in the RHS Plant Selector and others are listed below here:
- Buxus balearica – a vigorous, broadly upright shrub or small tree with glossy, bright-green leaves to 4cm (1½in) long. Most suitable for milder districts. Height 3m (10ft) by 2.4m (8ft)
- B. microphylla – a naturally compact form of box that needs no clipping to form a shrub. Small, narrow leaves to 2cm (¾in) in length, turning bronze in winter. Prefers some shade. Suitable for colder areas. Height and spread 75cm (30in) by 1.5m (5ft)
- B. microphylla ‘Compacta’ – a very compact, dense and slow-growing dwarf form. Leaves 1cm (½in) long. Height and spread 30cm (12in)
- B. sempervirens – a popular choice for larger hedges. Bushy, rounded shrub or small tree with glossy, dark green leaves to 3cm (1.25in) long. Height 5m (16ft) by 5m (16ft)
- B. sempervirens ‘Latifolia Maculata’ AGM – a compact mound-shaped shrub with bright yellow young foliage, maturing to dark green marked yellow. Height and spread 2.4m (8ft) by 2m (6½ft)
- B. sempervirens ‘Elegantissima’ AGM – a very dense, slow-growing, dome-shaped shrub with narrow, cream-margined leaves to 2cm (¾in) long. Height and spread 1.5m (5ft) by 1.5m (5ft)
- B. sempervirens ‘Prostrata’ – a strong-growing, spreading shrub suitable for ground cover. Height and spread 80cm (32in) by 3m (10ft)
- B. sempervirens ‘Rotundifolia’ – an upright shrub with large, glossy dark-green leaves to 2.5cm (1in). Suited for both clipping and informal plantings. Height and spread 3m (10ft) by 2.4m (8ft)
- B. sempervirens ‘Suffruticosa’ – a much slower growing cultivar suitable for parterres and small hedges. Traditional dwarf box, compact and very slow growing. Plants offered under this name can be variable and nurseries should be asked to guarantee compact habit. Alternatively, propagate from plant material that shows the desired characteristics. Height and spread 90cm (3ft) by 1.5m (5ft)
Height and spread refer to mature plants. All parts of the plant are poisonous.
The range of box (Buxus) cultivars: Far right (top to bottom): B. sempervirens 'Elegantissima', B. sempervirens 'Lace', B. sempervirens 'Wisley Blue'. Second row: B. sempervirens 'Prostrata', B. wallichiana, B. sinica var. insularis 'Filigree'. Third row: B. sempervirens 'Latifolia'
Buxus sempervirens 'Suffruticosa'
Buxus sempervirens 'Latifolia Maculata'
The following is a summary of the symptoms, pests and diseases you might encounter. Box blight remains the current, most serious problem.
- Excessive sunlight can cause discoloration and sun-scald to leaves
- General bronzing or an orange coloration of the foliage is also due to environmental stress usually following hot, dry spells in summer, although a contributing factor may be root damage due to winter waterlogging
- General yellowing of foliage may be symptomatic of waterlogging, especially on heavy clay soils
- Over winter, leaf tips and margins commonly yellow due to low temperatures
- Leaf discoloration will tend to be more common in exposed sites
- Young growth in spring can also get caught by frost, turning them pale brown and often papery-looking
An application of fertiliser in spring to encourage fresh new growth, along with clipping, usually rectifies these problems.
Roots subjected to waterlogging are usually a blue-black colour in cross section and fall apart when teased out. Damaged roots should be removed, top growth trimmed back and the box replanted.
Pest and diseases
Box may sometimes suffer from the following problems: box blight, box sucker, box tree caterpillar, plant establishment problems, red spider mite and scale insects. If in doubt, our page on box problems is a good place to start.
Common name Box
Botanical name Buxus sempervirens, B. microphylla, B. harlandii
Group Shrub, Hedge
Planting time Autumn or spring
Height and spread Up to 5m by 5m (16ft by 16ft), but can be kept smaller
Aspect Sun or shade
Hardiness Fully hardy