Britain in Bloom - Transforming Local Communities, has case studies of Manchester, Ahoghill, Brightlingsea, Cumbernauld Community Park, Glasgow Garrowhill Garden Estate, Dukinfield Central Estate, Holyhead, Nottingham, Kilsyth, Cemaes Bay and Newcastle-under-Lyme.
Half of the groups that responded listed transformation of disused, eyesore space used for crime as a benefit of participation. They listed a reduction in crime, an increase in community spirit, the feel for a place and sense of pride as benefits.
The report found BIB groups look after an average of 6ha of green space each.
Nearly 70 per cent do litter picks, 33 per cent care for street furniture and 25 per cent remove graffiti.
Around 115,000 trees, 352,000 shrubs and 21.6 million plants and bulbs are planted by groups annually.
Respondents on average raised £6,044 funding each, saving councils £6m a year.
Nottingham Council says it saved £69,400.