Bracken - Friend or Foe ?

I can feel a bit of a bracken rant coming on. Bracken (pteridium aquilinum to give it it's posh name) is primarily a woodland plant and in most countries it does not colonise open areas. But with our maritime climate and recent warmth it strays out of the woods and can be particularly invasive on open areas around the coast and on heath and moorland.

It's this invasive behaviour which has gained it a bad reputation as a weed, but it might surprise you to hear that there are few other British herbaceous plants that have been of such economic importance.


Managing bracken as a crop was a key part of keeping it in its place. Bracken has been used for bedding, flooring, feed (croziers and rhizomes) and as a compost and mulch. In the building industry it was used as packing, thatching and dried as a fierce fuel to fire bricks and tiles. It was even used extensively in Sussex for road foundations. But the most imporant uses in this area were to provide potassium for the glass and soap/lye making industries. For this the ferns were gathered in July and August and burnt in enormous bonfires to reduce to the ashes or potash rich in potassium.


The extensive harvest gave rise to many place names where the fern was an important crop, Farnham, Farncombe and Fernhurst are local examples.

There were strict rules and laws governing the harvesting of the crop to avoid damage to the future crop and allocate areas to individuals or families.

As the common land and heathland has fallen into disuse and the demand for bracken as a crop has disappeared the fern has advanced and colonised new areas. This is particularly true of restored heathland where scrub tree cover has kept the bracken down. Once the trees are removed the bracken invades.

After a few years the bracken can gain the upper hand and then we tend to use any means at hand to prevent the bracken from suppressing the new heather growth, and generally that means spraying it with a systemic pesticide, Asulox.


We now know that the bracken contains a number of toxins, as do many plants, at least one of which is carcinogenic so eating bracken (aside from the croziers, or youngest shoots, and the very well boiled rhizomes) is off the menu. Reasearch shows that the toxins in the plant build during the season and peak around July and August when the spores are thought to be carcinogenic. But bracken does not spore every year, and apart from pushing through dense stands of spore bearing plants in August it is very likely impossible to avoid the spores amongst the thousands of varieties in the air during high summer unless you stay in town or wear a mask. So the danger from bracken spores is very probably significantly exaggerated.


Alternatives to managing bracken by spraying are cutting manually, cutting mechanically and rolling. Four years ago we decided not to spray on the Lynchmere commons and since then have been experimenting with forms of cutting and rolling. Rather than attempting to eradicate all the bracken we are focusing our efforts into some key areas to reduce or remove it. Early indications are that this strategy is working well and with each year the bracken thins out, grows smaller and easier to manage allowing us to expand our management to more areas.

It seems unlikely that bracken will make a comeback as a crop of the economic importance it used to have, but to develop some use for it would improve our ability to harvest and remove it. So I am experimenting with methods of cutting and composting it in an attempt to produce a peat free seed compost. Anyone walking across the commons might come across one of the bracken ricks that Alison and I have piled up as a part of this experiment. We'll be turning them from time to time to encourage the decomposition and monitor the progress.