A tree disease which is spreading through the South West of England has infected an avenue of Horse Chestnuts at Avebury, leaving the National Trust with little choice but to remove it.

The avenue which runs along the A4361, north of the Avebury stones was planted by Alexander Keiller in 1937. He was the archaeologist and businessman who founded the Alexander Keiller Museum at the World Heritage Site. Today the southern end of the avenue is owned by the National Trust, the rest by a local landowner.

Tree inspections and laboratory studies have revealed the Horse Chestnuts to be in a poor condition and suffering from Phytopthora ‘bleeding canker’.

“The crowns and bark are dying and there is the tell-tale black sticky exudation oozing from the trunks, which sadly indicates the presence of bleeding canker,” says Hilary Makins, Head Warden for the Avebury estate.

“It did look like some of the trees were recovering from the disease or at least holding it in remission but the amount of bark loss and death has made many of the trees even more susceptible to attacks from pests, fungal decay or further infection, which means the branches are more likely to dry out and crack or drop without notice.”

Their height also suggests that they have been very slow growing for trees which are nearly 70 years old. This indicates either a poor quality site or other limiting factors putting them under stress.

For the last five years the National Trust has been trying to maintain and retain these trees through a programme of selected felling and tree surgery. However it is now clear that this is unsustainable and the charity has taken the tough decision to fell the remaining 28 trees.

Over the next few years the avenue will be replaced with a different species that’s more suited to the site or a mixture of species to create a dense screen.