Environmental Security
Environmental security or barrier
planting is a term that is commonly used to describe selective
planting made up of species that would deter unwanted visitors, and
create a screen to reduce the chance of being overlooked.
We have been using barrier planting
for centuries in the form of hedges to retain livestock and mark
out boundaries, these hedgerows are often seen as one of the
defining features of the English landscape.
A traditional view of the English countryside,
a network of hedges and woods.
They have normally been made up of a
formal hedge comprising of a mixture of native species e.g.
Hawthorn, Holly, Blackthorn and Hazel. They were maintained by
trimming on regular basis to prevent them from becoming open and
drawn, which could lead to gaps appearing, and breaks in the
boundaries. The hedges form a breeding ground for wildlife and
provide food and shelter throughout the year. Older hedgerows form
a network of safe passages and corridors for wildlife in between
woodlands and copse.
In the urban environment around
housing estates and industrial areas the choice of boundary marking
is seemingly endless. Walls of differing heights and build
materials, fences come in an array of differing materials from
wooden panel fences to steel palisade. The main purpose of these
fences today is to deter entry from unwanted visitors, or to guide
people to the desired point of entry.
A hedge created using Berberis
guiding people around to the front door.
Appropriate planting may be used to screen unsightly
fencing.
A hawthorn hedge used to screen the steel palisade
fencing.
Appropriate planting can also act as a secondary form of
defence to deter people from climbing over, and gaining
entry.
Pyracantha grown over an
existing brick arch
to form a secondary barrier and soften the hard
landscaping.
The plants will also help to reduce
noise levels and filter pollution. (visit the NUFU site for more
details) . Dependant on site of planting a wide range of
plants can be used. The choice of plants is wide and varied so
careful planning would be needed.
Things to consider:
- Planting site
Like any type of planting
the basic principles apply. The points to consider are position,
soil type, proximity to buildings and footpaths, soil type,
drainage of soil.
If the planting is to be done against a wall, fence or building the
future maintenance will need to be taken into account. Access to
the planting area in the future needs considering so machinery can
gain entry if needed and disposal of arisings can be done without
having to walk through the property.
The types of plants used need to fit in with the overall
environment, if the setting is semi-rural or out in the open native
plants should be used. A native plant is one that occurs naturally
in this country and therefore should establish and adapt to the
planting site better. Also regionally native plants will offer more
to the wildlife in offering food sources and shelter. (for further
planting information visit the backyard gardener web
site).
- Maintenance
Any form of vegetation will require a certain degree of
maintenance, in the early part of establishment watering, weed
control and mulching will need to be done. This will allow the
plants to have the best start and so overall impact should be
greater.
After this the level of maintenance will depend on the owners
preference but a fast growing species that needs to be kept clipped
in a formal hedge or clipped into shape as a specimen shrub would
be a poor choice and cost more in time and labour. Depending on
species choice this could be very time consuming and costly (visit
the
Urban Policy Unit site for more information about High
Hedges).
Choice of Shrubs
The shrubs listed below are just a
selection of plants that can be used, most are either a large shrub
or climbing plant these can be positioned together to form a
barrier or planted individually as specimens. Climbing plants may
be used to plant against walls or fences they need to be very
thorny or they may aid in gaining entry.
- Berberis - Form a dense shrub, which has
spines along the branches, and some varieties have spiny leaves in
addition. The shrubs have deciduous and evergreen varieties some
have brilliant flowers and autumn colour.
Clever use of pots to hide the caravan.
- Blackthorn - Native plant widely used in
hedgerow planting. produces white flowers in April/May followed
later in the year by fruits. The branches are armed with long
thorns.
- Chaenomeles - These shrubs are spined to some
extent and have a flowering period from March to May.
- Hawthorn - The traditional choice of hedging,
can be planted on its own to form a formal hedge., or mixed with
other varieties of plants to create a variation and encourage
wildlife.
Mature hawthorn
hedge.
- Holly - There is a wide variety of choice. The
plants can be clipped to maintain a formal hedge or be positioned
as a specimen on its own. Most are armed with spiny leaves.
- Pernettya - Medium size shrub with dark green
glossy leaves, retains its pink berries throughout the winter.
- Ponicirus - Angular stems which have broad
thorns along their length. The shrub has single white flowers in
May.
- Pyracantha - Forms a very dense shrub with
long singular thorns along the branches. All varieties have white
flowers in May/June followed by berries that can attract
wildlife.
- Roses - The wide variety of forms
available makes roses a good choice they can be planted as
standards, climbing and shrub. All form a dense framework of
branches covered in thorns.
Rose bushes.
- Rubus - Grown as a shrub with an arch forming
habit the stems have a white washed appearance. Single purple
flowers appear in June.
- Gorse - Medium sized shrub with green stems
covered in yellow flowers during April/May.
Choice of Trees
Trees can be used to create screens
to obscure views or prevent people looking in, the species listed
below carry a degree of thorn cover which may be an advantage if
needed to prevent people from climbing up them.
- Hawthorn - Crataegus x grignonensis a medium
sized tree growing to about 6 meters has white flowers followed by
large red berries. Crataegus prunifolia medium sized tree reaching
about 6 meters with a rounded crown. It has white flowers, which
appear in June followed by crimson berries. The leaves turn a
red/orange colour in the autumn.
- Honey Locust - Gleditsia triacanthos large
tree which tolerates most conditions. The mature tree carries
thorns along its length.
- Robinia - Robinia psudoacacia mature tree
carries a very deeply ridged bark the younger growth is armed with
thorns that are arranged in pairs along the stems.
Robinia
Tree
One of the worlds largest plant
databases available on the Web is found at
www.neoflora.com
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