Cycling the Canal du Midi. Declan Lyons

the trees as it goes. The fungus was carried to France in wood used to make munitions boxes in the US for the allied troops in Europe during WWII. It was first identified in Marseille in 1945 and appeared on the canal near Carcassonne in 2006. It has spread rapidly since. The canal company has been forced to fell more and more infected trees. Once infected, a tree dies within three to five years and then poses a safety risk. The company sees little chance of saving any of the 42,000 plane trees that shade the canal’s towpath.

      The trees are felled between October and March each year. The path adjacent to the felling is closed during this period and diversions are usually signposted. Cyclists should not enter the cordoned-off areas during these works. The works bring heavy machinery onto the towpaths and these can cause further damage to the surface. Disease-resistant plane trees and other species are being planted after the diseased ones are removed, but it will take decades before they provide proper shade.

      The felling is occurring along the length of the canal and it is impossible to predict which stages of the cycle will have good shade. Cyclists should assume that there will be stretches where there will be very little shade. The first edition of this guide indicated the shade level on each stage; it is not possible to do this in the current edition.