Bracken is a very successful and invasive plant. Although it provides a beneficial habitat to some species in its own right, over the past years it has started to colonise much larger areas. The danger is that it is shading out and killing off the heather, thus destroying the habitat for a much wider range of wildlife. Bracken has minimal feeding value – and it's not too good for walking through either!
The object of bracken management is to control its spread, and the methods used are rather different to those used on the heather. Bracken is a fern that grows from underground rhizomes which have a great ability to regenerate, which means they are difficult to get rid of – if you've ever tried to clear your garden of ground elder or bindweed you will understand the type of problem! Simply burning the bracken has little effect, in fact it can encourage new growth, although it is used for clearing bracken litter. Simply cutting the bracken yearly has no significant effect, although more frequent cutting can weaken it.
Bruising is recognised as the most effective method of controlling regeneration. If the fronds can be damaged so as to bleed sap the buds on the rhizomes are less able to produce rapid growth. Traditionally this was done by dragging a log behind a horse, or cattle allowed to trample on it. Recently a crimping machine has been used to make a more effective job. This has to be done twice a year and is not possible on the steeper gradients.
Spraying with herbicide is also undertaken and, although it was not the first choice of management technique, can be very effective. Indeed large areas of the Quantock Common have been sprayed from the air. A more recent development is the weed wiper, towed by a tractor or quad-bike, which allows closer targeting but is limited by terrain. Unfortunately it is difficult to rule out chemical control where bracken presents a serious threat to the heathland.
From an article about the Quantocks. Apparently pigs, or boars are effective as well.
