Robinias have recently been in the press as there has been a sudden and relatively unexplained decline in the species.
While no definitive answer has been found, there has been some suggestion that the decline is caused by a ‘vascular wilt disease’ caused a soil borne fungus (Verticillium spp.).
Vascular wilts are exremely serious diseases that can cause rapid death of whole populations of tree – ‘Dutch Elm disease’ is a vascular wilt.
Some have conjectured that the uncommonly wet weather of the last few years has either made conditions for the fungus more favourable, or stressed the trees making infection more easy, since Robinias like well drained sites.
If this is so, the weakened trees are also likely to be more susceptible to infection from root diseases Honey Fungus (Armillaria spp.) and Phytophora, in addition to other diseases which already affect the tree.
At this stage, little can be done for the trees while research continues, but hopefully the species will not go the way of the Elm; though since it is native only to North America, its loss will not be quite so severe for the British countryside.
