Pen-y-crug Iron Age fort is one of 27 Iron Age forts within the area that is the Brecon Beacons National Park. Pen-y-crug is a large multivallate (many defensive banks and ditches) Iron Age hillfort situated in the Usk Valley to the north west of Brecon town.
Pen-y-crug is impressive, to say the least. Have a look at the flyover video below to see!
The problem is that – and you can see this in the video – Pen-y-crug is overgrown with bracken.
It may not appear to be the biggest of problems, bracken; it dies back in the winter doesn’t it? Well, yes, the foliage dies back every year but during the spring and summer months the bracken covers Pen-y-crug making it impossible to even notice whilst visiting the site that it is in fact an Iron Age fort.
Again, this may not seem like a massive problem. Does it matter if you can’t see the ramparts and ditches? On a basic note, if one cannot see the extent of the fort can one appreciate its importance? But, stepping away from the general aesthetics and observation question, bracken growth is detrimental to underlying archaeological remains for one particular reason.
Utter that word to archaeologists and you’re likely to see a look of pain flit across their face, hear a sharp intake of breath and possibly a response along the lines of ‘Oh, don’t talk to me about rhizomes!’. They are not good news.
So why are rhizomes so bad? A rhizome is (apologies for the Wikipedia quote) ‘a modified subterranean stem of a plant that is usually found underground, often sending out roots and shoots from its nodes’. If it helps to visualise this think of ginger-like roots growing under the surface of the ground. As you can probably imagine these creeping rootstalks grow rather extensively underground and can cause considerable damage to underlying archaeology deposits. Rhizomes can grow to a depth of one meter and can form up to 90% of a bracken plant, so imagine how many of them there must be at Pen-y-crug!
The most effective long-term way to get rid of bracken is to spray the fronds (leaves) with a saline based herbicide called asulam. This involves spraying the bracken fronds with the herbicide. Treatment isn’t obvious to begin with; the herbicide works its way through the plant to the rhizomes and subsequently stops the bracken re-emerging again next year. Hopefully, thanks to the hard work of the Brecon Beacons warden team, there will be a lot less bracken and Pen-y-crug’s ramparts and ditches will be a lot more visible next year!