well as offering protection from the elements, screens, whether
natural or prefabricated, can be used to enclose the garden both
vertically and horizontally, and to define axes and vistas. They
give the garden form and, by concealing parts of it, make it more
interesting, imparting an air of mystery and inviting exploration.
On a slope they may be used to give a feeling of stability.
Pergolas, walls and hedges all provide microclimates due to the
shade they cast, the protection they give from the wind and, in
the case of south-facing walls, the heat they give off as infrared
have certain advantage over hedges. They are built quickly and do
not change their height or width with age. Since they have no
roots, they do not interfere with the growth of plants at their
foot and you can grow plants up them. Neither do they suffer from
disease. In sum, you trade a high initial cost for low
only do hedges have a more natural feel, they serve as a refuge
and resting place for birds. But while hedges are comparatively
cheap and easy to start, slow-growing species, such as box, may
take ten years to reach a reasonable height while fast-growing
ones may need trimming several times a year. Most need watering
and some need periodical spraying with insecticides.
care when planting a hedge along the edge of a terrace. If this
has been properly made, the carefully fitted large blocks that
form the face will be backed by as much as 1m/3ft of loose stones.
Do not plant within 1.5m/5ft of the edge of the terrace, at very
minimum, in order to avoid this band of stones. Moreover, cutting
the top of a hedge along a terrace will be much easier if you can
lean the ladder on the outside of the hedge with its feet on the
top of the wall. Hedges should always be cut with a face that
slopes inwards towards the top, to prevent the base dying and, on
terrace edges, to avoid them overhanging the wall at the base in
an ungainly fashion.
Latymer: Walls, hedges and pergolas, in The
Mediterranean Gardener, F. Lincoln, London, 1990.