Imagine if you will a plant that can cause cancer and is rich in cyanide. It is a plant which has gradually taken over vast areas of one of our most popular National Parks.

Its foliage strangles upland grass growth reducing the productivity of pasture for fell farmers.

Yet man appears to do little to limit the spread of this plant. The plant in question is of course bracken.

After bracken clearance

Before bracken clearance

What makes man's inaction even more bizarre is the fact that bracken has colonised all the very best upland soils on the fells. It especially likes the deeper blacker soils that were created under long since vanished mixed oak woodland. So if you want to see where the best sward of grass could grow on the Lakeland fells look to those areas inhabited by the bracken. It always favours soil deeper than nine inches in depth.

But the issue of bracken control is not regarded as straightforward by the experts. The largest landowner in the Lakes, the National Trust has in the past encouraged its tenant farmers to use a new chemical Azulox to kill bracken, but now they fear other ramifications of this form of bracken control.

Bracken derives its name from the Anglo Saxon Brake, meaning uncultivated land.

It is Britain's most abundant fern and started its take-over bid as early settlers slashed and burned clearings in woodland across Britain. Before this bracken had been a much rarer and taller plant grabbing odd habitats in the forest.

Its roots contain a mixture of poisonous cyanide salts and carcinogens. As a result grazing is avoided by sheep, cattle, rabbits and insects, its only enemy being frost.

This frost threat does stop the bracken spreading much above 1,000 feet.

Just a hundred years ago bracken was still fairly marginal because there were more cattle grazing and trampling down the bracken shoots and farm manpower was greater to cut the bracken to use as winter bedding for the cattle. It's use for bedding even meant specific enclosures were deliberately turned over to the bracken for repeated harvesting.

As Pearson and Pennington state in their landscape study bracken was cut by hand by the Victorians and this kept the plant under control. They recall: "When there was more and cheaper labour than today many of the fell sides which are now so unproductively
covered with bracken were some of the best grassland in the Lakes.''

Under its folded leaves bracken creates millions of spores released on warm summer nights (July and Aug). Supposedly on the Eve of St John. Its roots are tough wiry rhizomes which spread through the old dark soils. In times of dire famine these roots were dried and ground up to add to flour, perhaps on the principle that it was better to die of cyanide poisoning than of hunger!

Bracken loves acid soils hence its failure to overwhelm the limestone hills in the Yorkshire Dales in the same way it has in Cumbria.

Thanks to man's neglect many commons and even enclosed stinted fields have been overwhelmed.

Inquiries to the Ministry of Agriculture at Carlisle on the topic drew a blank with no readily available information. Enquirers being referred to their York offices and this despite the fact that ESA (Environmentally Sensitive Area) grants are available to
help with tackling bracken.

But the National Trust's local expert John Houston is fully aware of the benefits and pitfalls of trying to deal with bracken infestation.

"Azuloz is transferrred down from the fronds down to the rhyzome, thus very effectively killing the plant, but unfortunately it also kills other ferns and these are ecologically sensitive, so we have to take great care.

"It is true to say that some of our best land has gone under bracken, but it is a complex issue. Our tenants have, in the past tried bracken control and we have supported them. There have even been aerial and tractor based sprayings.But if they spray and op
en fellside, in ten years time they are back to square one with the bracken.

"Another aspect is that once the new bracken is killed the thick underlayer of dead bracken prevents grass regenerating. If nothing recolonises then we have the problem of erosion to watch out for.''

He added: "My feeling is that bracken can only be managed in carefully targetted areas. We and the farmers want to see land return to grazing, but one brief spraying is not the answer. Other concerns with aerial spraying is that the Environment Agency will
not allow such spraying within 50 metres of a watercourse, which rules out most of the Lakes!''

January 2006: Feedback Comment received by Lakestay: "Bracken is an increasing national problem and probably now occupies some 2 million hectares (8% of the UK land area), mostly in the uplands.

Asulox, mentioned in the article, is not "new": it has been around for more than 40 years and remains an essential tool in the management of bracken. It still offers many crucial advantages over the alternative mechanical control measures. Successful use of chemical requires specific approaches to bracken management which need not result in the useless waste of resources created by helicopter spraying every 10 years or so. It is possible that I can make practical suggestions that would be of assistance in these matters. I have yet to encounter any bracken that cannot be dealt with if both the land managers concerned and other interested parties really want to make progress !"
Regards, Dr. Roderick Robinson
Treasurer of the International Bracken Group
c/o International Application Technology Group,
Bayer CropScience, Cliffe Road, North Newbald, York, YO43 4TY, England

In some parts of the UK the National Trust has supported cutting back this invasive plant, but not to our knowledge in the Lake District.