Here is some advice from Leeds Allotments Federation about coping with the corona virus emergency on your plots.
Follow Government Advice at all times, and remain at a distance of at least 2mtrs from other allotment holders. Don’t gather in sheds. Use hand sanitiser or soap & water as you enter and leave site. (We can’t supply this at the moment due to the panic buying). Be mindful of other allotment holders who may need help if they can’t get to site regularly. If you are displaying any of the symptoms associated with Coronavirus stay away from site until you are clear & if you decide to self-isolate for 12 weeks let your committee know via email/text so they know you won’t be around for a while and won’t hassle you over your plot not being cultivated.
Please be respectful if people don’t want to engage in conversation and don’t go onto anyone else’s plot unless they invite you. This is a situation which is changing daily and we need to ensure our own and other people’s safety.
The National Allotment Society also has a page about Covid 19 Emergency Measures with a list of important precautionary measures.