Floral alleys can transform cities (credit: NW in Bloom/RHS)

Gardeners at the RHS London Plant & Design Show on 14-15 February were urged to turn neglected alleyways into green havens.

A poll of 231 gardening groups found that run-down areas were problematic due to fear of crime.

But gardens at the event showed how to green-up grot-spots.

One designer said: “A derelict alley can be taken on as a community project.”