It may be the Main Avenue show gardens that get all the headlines during the week of RHS Chelsea Flower Show , but this year, one container garden is highlighting an important – and often overlooked – message. According to new research by Flood Re, the organisation behind the gold medal-winning Flood Re: Contain the Rain garden, millions of homeowners in the UK could be 'sleepwalking into a flooding crisis'. Flood Re says 82% of garden owners in the UK think their plot would cope with heavy rainfall, but almost one in three don't realise paving and other hard surfaces can boost the risk of flooding – and just 3% consider flood risk when planning their garden.…