Any Ideas?
Health and safety at work act
RIDDOR
COSHH
etc?
Environmental Protection Act
Wildlife and Countryside Act and Countryside Rights of Way Act
Control of Pesticide Regulations (think that's part of EPA)
Common Agricultural Policy
Working Time Directive
Environmental Permitting Regulations
Town and Country Planning Act especially agricultural permitted developments
the various Agriculture Acts
Just did a quick search and got all these.... have not read them but they may be what you are looking for, especially the first one???
http://www.google.co.uk/search?sourceid=navclient&gfns=1&ie=UTF-8&rlz=1T4ADFA_enGB344GB344&q=horticultural+legislation
Shouldn't forget the various Small Holdings Acts starting with the Small Holdings and Allotments Act 1908!