The factsheet I've attached to this post - which you can download - has been produced with the Community Land Advisory Service and endorsed by the Department for Communities and Local Government.
It is designed and intended to provide general information on various legal issues concerning allotments, current at the time of publication. The contents do not constitute legal advice, are not intended as a substitute for legal advice and should not be relied on as such. You should seek legal advice in relation to your individual circumstances and any particular matters you may have.
A great fact sheet for any group thinking of setting up a new allotments site.