The tall upright leaf stalks of this perennial arise from horizontal rhizomes which can extend over a large area. Effectively the whole of the topgrowth is a leaf and the stout upright part is the leaf stalk, it is bright green at first and becomes brown as the leaf matures through the summer. They can be from 50 to 200 cm tall, depending on the local conditions. The bright green leaflets grow almost horizontally and have many subleaflets diminishing in size towards the tip to form a triangular shape.
As well as the potential allergic properties of the spores, bracken harbours the ticks which pass Lyme disease to humans. The spores have also been implicated as being carcinogenic. The foliage is poisonous to grazing animals which can easily take in the young unfurling fronds - it has been shown to cause bladder and intestinal tumours in such animals. For this reason it would not be welcome in land intended for fodder production.
Bracken is resistant to many herbicides and recovers from digging due to the extensive underground system. An isolated patch can be removed eventually by continual mowing, which exhausts the rhizomes. Liming the soil can deter it as it prefers acidic conditions. However as it is usually encroaching from hedgerows or adjoining scrubby land it is difficult to remove; a vertical barrier would have to go down very deeply to defeat the rhizomes. If it is possible to keep a clear patch beyond the boundary of the garden it should be kept at bay.
Weedkillers to use:-
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