Suitable plants for screening can include hedging shrubs, trees or grasses and bamboos, depending on the level of formality, and the height and spread required for the space.
A useful way of using large shrubs as tree substitutes is to clear the lower branches as they grow so that the space underneath is maximised and plants below receive adequate light. This is especially effective as a means of continuing screening above a 1.8m (6ft) standard boundary fences. The canopy then branches out above the fence.
Arbutus unedo AGM: This has white flowers from October-November and red fruits. Height 8m (24ft).
Eucalyptus gunnii AGM: The adult leaves are long and grey-green and juvenile leaves rounded and mid-green or grey-green. Height 10m (30ft) to 25m (80ft).
Ligustrum japonicum: This shrub has dark green glossy leaves which are upright and dense. White flowers from mid-summer to early autumn. Height and spread 3m (10ft) by 2.4m (8ft).
L. lucidum AGM: has bright green leaves. White flowers up to 20cm long (8in) in late summer to early autumn. Height and spread both 10m (30ft).
Magnolia grandiflora: has leathery, glossy green leaves with felty brown undersides. Large, white, scented flowers are produced from late summer to autumn. Height and spread 6-18m (20-60ft) by 15m (50ft).
Olea europaea: is a slow growing evergreen tree with grey-green leaves, reaching a height and spread both 10m (30ft).
Photinia × fraseri 'Red Robin' AGM: is a compact form of Photinia with bright red young leaves. White flowers are produced from mid- to late spring. Height and spread 5m (16ft) by 5m (16ft).
Prunus laurocerasus 'Rotundifolia': is vigorous and makes excellent screening, becoming tree-like after some years. It bears fragrant white flowers from mid- and late spring 5m (14ft) by 4m (13ft).
Quercus ilex AGM: is a rounded tree with smooth bark. It responds well to being pruned. Height and spread 25m (80ft) x 20m (70ft).
Trachelospermum jasminoides AGM: is a vigorous, twining climber with glossy dark green leaves that turn bronze-red during winter. Fragrant pure white flowers are produced from mid- to late summer. Height and spread 4-8m (12-25ft).
Grasses and bamboo
Grasses and bamboos, if chosen carefully can provide an attractive screen that, in a breeze, adds movement and sound to the garden.
Miscanthus sinensis cultivars such as the 2m (6½ft) tall M. sinensis ‘Silberspinne’ and the 1.5m (5ft ) M. sinensis ‘Morning Light’ make an informal screen for summer.
Take care to choose species that will form clumps and not become invasive.
Chusquea montana: is clump forming and has a tidy compact upright habit. Height 1-3m (3-10ft): average height 2m (6½ft) at Wisley. It spreads 75cm-1.5m (30in-5ft) in 10 years.
Fargesia murieliae AGM: is a clump-forming bamboo with small leaves reaching a height and spread of 4m (13ft) by 2.5m (8ft).
F. nitida: is similar, but may not grow quite as tall (2-4m (6½ft-13ft)) as F. murieliae.
Small trees that are suitable for the smaller garden, perhaps to intercept the view of a neighbour’s extension include:
Crataegus persimilis 'Prunifolia' AGM: has crimson fruits and good foliage colour. Height: 8m (26ft).
Malus 'Evereste' AGM: has white flowers in late April, followed by yellow fruits. Height 7m (22ft) by 6m (20ft).
M. × robusta 'Red Sentinel' AGM: has long-lasting red fruit 2.5cm (1in) across. Height 7m (23ft)
Prunus 'Umineko': is a narrow-growing, upright tree with white flowers in spring. Height 8m (26ft).
Pyrus salicifolia 'Pendula' AGM: has silvery-grey foliage and a weeping habit. Height 5m (16ft).
Sorbus aucuparia 'Sheerwater Seedling' AGM: is a vigorous, upright small tree with compact ascending branches with red-orange berries and autumn colour. Height 10m (33ft).
S. vilmorinii AGM: has rose-red to white fruits and good autumn foliage colour. Height 5m (16.5ft)
Exposed coastal situations
The choice is more limited by the coast, but the attractive low-branched, spreading Pinus radiata (Monterey pine) will thrive as will Quercus ilex (holm oak) but this may be rather slow growing early in its life. However, it can be hard pruned and even topiarised in later years.
For large-scale screening
Where space is not a problem a mixed screen of some depth can be planted. For example, silver birches (Betula Pendula) and Scots pine (Pinus sylvestris) interplanted in two rows 4.5m (15ft) apart can be very effective especially when underplanted with cotoneasters, viburnums and poplars which can be removed as the screen develops. A more formal approach might include Catalpa bignonioides 'Aurea', Davidia involucrata, Fagus sylvatica 'Fastigiata', Quercus rubra, Prunus padus or Sorbus aria 'Lutescens'.
Shady sites on poor soils
Shady sites can be challenging, but consider the evergreens Prunus laurocerasus, Ilex aquifolium or Taxus baccata. These can be planted as a dense hedge or as an extensive screen that will tolerate hard pruning. Where there is more sun, consider Elaeagnus × ebbingei or E. pungens for screens up to 4m (13ft). These also tolerate hard pruning.