Walking along a narrow and little used lane, I looked at the plants growing along the verge – a variety of grasses, buttercups and the occasional late dandelion, convululus (hedge and field varieties), dock plants, cow-parsley and hogweed – all of which I’m sure are beneficial for wildlife. But what I can’t judge is whether this diversity of wild plants is good or not so good – it’s hard to judge what’s not there!
However I am encouraged by the following observation made by the Natural History Museum: “Road verges cover an enormous area in the UK – they span about 500,000 kilometres, equivalent to driving more than 12 times around the Earth! Their total area is thought to be slightly larger than the Lake District National Park. Museum botanist Fred Rumsey says, ‘The sheer scale of the road verge habitat in the UK is pretty mind-boggling. In terms of providing habitat for our threatened wildlife, this huge network of linear strips is increasingly important.’” (1)
Warwickshire Council has a scheme for improving biodiversity by focusing on encouraging wildlife friendly verges – https://www.warwickdc.gov.uk/info/20855/biodiversity/2016/wildflower_verge_trial
(1) https://www.nhm.ac.uk/discover/why-road-verges-are-important-wildlife-habitats.html