Nurseries have had to deal with occasional plant health worries for ever. Fire blight was the issue in my youth. More recently we've had to contend with sudden oak death and ash dieback. Currently concern is focused on Xylella. Our authorities have always had power to take action and, now and then, nurserymen have fretted at the actions those authorities took or threatened to take.
I'm not quite sure what's changed - whether the threats are genuinely greater than they were (it's difficult to think of anything much worse than Dutch elm disease) or whether international trade makes the threats more likely, or whether science has given us greater understanding of the threats and their consequences - but one way or another plant health threats are now being treated more seriously than ever.
Landscape contractors are being made aware because in the case of seven common tree species our plant health inspectors are now obliged to randomly inspect a given percentage of all imported stock after they've been planted on site. Contractors are now receiving phone calls and being asked where trees are planted because an inspector wants to see them. This action, for the first time in my memory, has made contractors aware that they too have responsibilities under our plant health legislation.
In this age of litigation it is not good enough that a nursery, contractor or garden centre takes its responsibilities seriously. If there's a problem they have to demonstrate that they do so - and that's not so easy.
To do that you have to formally recognise your responsibilities, work out how you'll discharge them and then record that you do. The regulations have obliged us all to do this for a long while, but to date we've not been held to account. The most important change taking place in the world of plant health is that we will be held to account in the future.
Tim Edwards is chairman of Boningale Nurseries