TWO Penarth garden designers will be flying the flag for Wales at the world's greatest horticultural extravaganza - the Chelsea Flower Show.

Architect Barry Mayled, of Augusta Road, and Jo Penn, of Albert Crescent, have both been invited to design and build gardens for this year's show which will take place from May 23 to 26.

The Penarth entrants are the only ones from Wales to the highly-prestigious event - which attracts thousands of applicants from around the world.

This is the third time Barry has entered the Chelsea Flower Show but the first for Jo, a mother-of two who runs Jo Gardens.

Jo's entry is called The Mitie Garden, named after her sponsors in the chic garden category.

In 2003 Barry's city garden, sponsored by the Sir Steve Redgrave Trust, won a gold medal.

He took silver the following year with his London 2012-backed chic garden.

This year Barry has teamed up with Pencoed-based insulation manufacturer Rockwool to create an energy-efficient home extension as an alternative to gas-guzzling conservatories.

The Rockwool Garden Room, complete with roof terrace, will be the main feature of Barry's 150 square metre showpiece garden, with a central fountain and carefully co-ordinated borders of flowers.

The Garden Room is designed to retain heat in winter and stay cool in summer.

A leading housebuilder has already expressed interest in adopting the design.

Barry said: "More than 150,000 conservatories are added to houses in the UK every year but many homeowners underestimate the cost and environmental impact - of heating and cooling their glass extensions.

"We want to show an imaginative alternative."

Barry is also responsible for designing another entry - the Horticultural Research Institute of Warwick University garden, on a biodiversity theme.

This includes a surfboard made from brassica oils.

Jo, a former teaching assistant at Evenlode Primary School, is a graduate in garden design from UWIC.

Her garden, reflecting global warming, will include less hardy, succulent plants which can be grown across the UK thanks to milder winters.

She said: "I was thrilled when the Royal Horticultural Society offered me a place.