Walking through the historic remains of Pompeii makes you wonder how it’s survived so long. Buried for almost 2,000 years by a deadly shroud of rock and ash spewed out by the volcanic eruption of Vesuvius, Pompeii has since staggered – but not surrendered – under an onslaught of successive disasters.
Its ruins were marred further by Allied bombing raids in 1943, and smashed again by a powerful quake in 1980. More recently, rampaging vegetation spawned by Pompeii’s extraordinarily fertile soil has eaten into walls, foundations, floors and ceilings.
This botanic explosion posed as significant a problem for the Italian UNESCO World Heritage Site as the footfall of over two million tourists who visit it each year.
In the 1980s, waves of weeds and vegetation threatened to swamp the site: ivy, brambles, broom, bindweed and wild fennel were among over 30 types of parasitic plant invading Pompeii’s ancient buildings.
Brambles and fennel gripped the tops of walls, weakening masonry and causing it to fall; ivy pulled wall facings away; other vegetation popped open mosaic floors and tore them up after taking root. Once more Pompeii was under threat.
Surges of weeds
Simply ‘gardening away’ the problem was not enough. The fertile Vesuvian soil meant culled vegetation would quickly be replaced by new surges of weed. Conventional weed-clearing using heavy mechanical equipment was impossible because it would damage the already crumbling buildings.
Pompeii’s Department of Cultural Heritage called in weed experts, who came up with a rescue plan to eradicate harmful weeds with an innovative biodegradable herbicide and to restore some of Pompeii’s original vegetation.
The herbicide contained glyphosate which, when applied, travels to the roots of weeds where it blocks an enzyme the plants need to photosynthesise and grow.
Cleared of infestations
Without access to this enzyme, the weeds simply shrivel and waste away to the ground. Any glyphosate left behind gets broken down into natural soil components such as carbon dioxide and phosphate.
The herbicide is also easy to apply, as no specially trained personnel are needed, and the process requires only limited maintenance in subsequent years.
Pompeii’s Palaestra – ‘training area’ – next to the gladiatorial amphitheatre was the first focus for glyphosate treatment, and the results were spectacular. Today the site is clear of weed infestations, its grass green, clipped and pristine in the hot Campanian sun.
Simply ‘gardening away’ the problem was not enough. The fertile Vesuvian soil meant culled vegetation would quickly be replaced by new surges of weed.
In fact, the results were so good that the Department of Cultural Heritage was encouraged to apply the herbicide elsewhere in Pompeii, clearing away weeds to reveal more of its architectural splendour. And what a difference it has made.
Visit Pompeii today and the glories of this gem of the Roman Empire are on dramatic show: the Amphitheatre and Palaestra, of course; the Forum; the Temple of Isis and the Doric Temple; Pompeii’s two theatres; well-appointed private homes, such as the House of the Faun and the House of the Vettii; and the magnificent mosaic floor in the vast hallway of the House of Paquius Proculus, which is decorated with birds.
The conservation challenge
Despite these wonders, the conservation challenge remains enormous at Pompeii. There are 15,000 buildings and 20,000 square metres of wall paintings to protect. So structurally weak are many of the buildings that only some 30 per cent of Pompeii is fully open to visitors.
Thanks to the herbicide programme and other protective procedures, this tough little town lives on after a volcano’s anger tried to destroy it. If the EU bans glyphosate, Pompeii will again be endangered, this time by angry weeds – as could so many other ancient attractions around Europe.