|
Bracken (Pteridium aquilinum) is one of the
commonest ferns in Europe. It sends up large triangular
fronds from a wide creeping underground rootstock and
often grows in extensive, closed communities. As it
requires well-drained soil it is often found growing on
the sides of hills.
Bracken is an important and natural
part of our landscape. Within habitat mosaics it can be
important for many forms of wildlife including birds
such as the nightjar and whinchat, and can support rare
fritillary butterflies which depend on cow wheat and
violets as their sole food plants. It was originally a
woodland species, however it’s often a vigorous and
aggressive competitor and now occurs in a wide range of
habitats in the UK. It poses a significant threat to
many species-rich grasslands.
Problems:
-
Can reduce the area available for
grazing livestock.
-
Can encroach upon other important
wildlife habitats such as heathlands and grasslands.
-
Can harbour sheep ticks which can
cause disease in livestock and humans.
-
Can be toxic and carcinogenic to
stock and have a negative impact on human health.
Control Methods:
Techniques depend upon the extent of
the bracken and the habitat that you’re trying to
restore. The trampling action of livestock can go a long
way to help keep bracken in check and is an important
part of long term control. However where bracken is
extensive or no livestock are available other measures
will need to be considered. A variety of both mechanical
and chemical bracken control methods exist, depending
upon the extent of the bracken, topography and money
available. It is also key to consider the proximity to
water courses, the presence of nesting birds and the
presence of other ferns that are of interest.
1. Mechanical Treatment
Cutting/crushing/bruising. To be
effective it is necessary to cut/roll/flail the bracken
twice in the first year, in May/June and again in
July/August, followed by one cut each year for the next
few years. This should not be done if ground nesting
birds are present and health and safety guidelines
should be followed (bracken is thought to produce
carcinogenic spores from July to September).
|
For large areas bracken
ploughing and burning techniques are also
sometimes used.
The treading action of
livestock is also useful and winter feeding can
be used to attract stock onto the site. This
will help damage bracken buds or fronds that are
close to the surface and mean the litter is
disturbed and broken up encouraging frost
penetration to rhizomes. |
 |
2. Chemical Treatment
Alternatively, spraying bracken, using
herbicides is sometimes advocated. Asulam (Asulox) is a
selective herbicide and has relatively little permanent
effect on underlying vegetation, but it will kill other
ferns. Spraying should be done after the bracken fronds
have fully expanded to ensure maximum absorption of the
chemical. This usually occurs between late July and late
September.
A variety of application methods are
available depending upon the extent of the bracken and
site topography. For large, dense stands a tractor/ATV
can be used to tow a roller with wiping gear (weedwipe)
and on smaller, patchy stands, knapsack sprays can be
used for the targeted treatment of fronds.
A combination of mechanical and
herbicide application is often the most effective
strategy. However it is crucial that monitoring and
follow up treatments, together with grazing management
is employed to ensure a long term strategy to retain
control.
Please contact GWT for more
information on bracken control.
|
