Flower show's answer when nature calls

At the Royal Horticultural Society headquarters, thoughts have already turned to spring and the 2011 Chelsea Flower Show.

With plans to launch a new category of show garden for 2011 – called the Artisan Garden – one designer is taking the instruction to use natural, sustainably-resourced materials at its most fundamental level, by creating a garden incorporating a lavatory.

Korean designer Jihae Hwang's project is entitled "The Hae-Woo-So (Emptying One's Mind: Traditional Korean Toilet)". It's filled with wild flowers, grasses and Hedera – or ivy – which "cleans the air and promotes sustainability of micro-organisms". Ivy is useful in any garden, both as a food and a habitat for wildlife.

The lavatory proper is an attractive wooden structure set at the end of a path which leads through the flowers. According to the designer, it thus allows the act of emptying oneself to take place in the most natural and free setting. The concept is to capture more than the simple function of the lavatory, by attempting to tell the story of the inner self: Hae-Woo-So refers to a place where you empty your mind.

The lavatory is not just symbolic, however. It is the major structure in the garden and is designed to serve a functional purpose – making fertiliser from human waste. Its entrance is deliberately low, which ensures that users have to bend their heads and lean forward as they enter, in a gesture of humility. Outside, there is a traditional granite bowl that serves as a water fountain, where the water can be used as a natural bidet.

The RHS is often accused of being po-faced, but Bob Sweet, RHS head of shows' development, takes a robustly matter-of-fact view of Ms Hwang's theme. He said: "In any year exhibitors bring many diverse interests to the show, both in terms of plants and cultural references and this garden brings a further element to RHS Chelsea's already outstanding repertoire for 2011."

Other Artisan Gardens will include The Basildon Bond Garden, which pays homage to the birthplace of one of Britain's most famous writing-paper brands at Apsley Mill in Hemel Hempstead.

The brand's signature blue is the colour theme, picked up by grasses and Iris and, appropriately for a garden associated with letter-writing, there will also be a post box. The designer is William Quarmby, RHS National Young Designer of the Year 2010 runner-up. Kati Crome and Maggie Hughes's "A Postcard from Wales" is inspired by Dylan Thomas's home town of Laugharne. The garden features fruit trees, common salt marsh plants and pathways made from Welsh slate slabs with cockleshell edging.