What happens to a Chelsea show garden?

The exact cost of individual gardens at the Chelsea Flower Show is shrouded in secrecy, but with estimates of £200,000 upwards, where do these pricey exhibits go when the show is over?

Chelsea is renowned for its extravagant gardens filled with the best plants in the country, eye-catching sculptures and innovative landscaping.

The colourful event takes place over five days and is a whirlwind of blooms, blossoms - but no umbrellas this year - as the horticultural world removes its muddy wellies and gathers to celebrate the glamorous side of gardening.

But how do you make 80ft (24.3m) planted pyramids such as Diarmuid Gavin's Magical Tower Garden disappear when the curtain falls on the Chelsea drama?

These exemplary gardens attract interest from influential quarters and occasionally a wealthy admirer will purchase one wholesale.

In the 1950s, the Duke of Windsor - formerly King Edward VIII - was taken with a fashionable rockery and had the whole exhibit relocated to his private estate. He was so enthused that he even helped to move it himself.

"It's very rare to be able to sell a garden in its entirety," says Mark Fane, director of plant supplier Crocus, and veteran Chelsea contractor.

"The only time we did that was when the Karl Lagerfeld Chanel garden was sold to a private client in 1993."

Some of the plants are sold off when the 16:00 bell rings on the final afternoon, leading to astonishing scenes of a usually staid Chelsea crowd jostling for prize-winning flowers and sought-after plants.

Other plants have been borrowed from growers, or are needed for valuable seed collection later in the season.

Truck loads are returned to the nurseries, where herbaceous plants undergo the revitalising "Chelsea chop", before being sold on.

Finding homes for the structural elements presents a complex logistical problem and thoughts turn to disposing of the long-awaited show gardens before they have even been built.

Seasoned designers and contractors remember majestic trees being dumped unceremoniously in skips along with expensive timber, huge slabs of marble being discarded and whole hedges being abandoned on the pavements surrounding the showground.

This kind of wastage isn't tolerated these days. The Royal Horticultural Society (RHS), organiser of the annual event, now encourages environmental responsibility and show-winning gardens are planned with sustainability in mind.

Mature tree specimens, sculpture and garden furniture may be auctioned off for charity, or are donated to charitable gardens and communal spaces.

Other features find their way back to the sponsors' City head offices, while certain components sit in storage for months, even years, waiting to be re-homed or sold on.

"Sustainability is a good idea but not everyone has the money to do it," says Cleve West, designer of the Best in Show Brewin Dolphin Garden.

Sustainability is a good idea but not everyone has the money to do it... sometimes it's just easier to put it on a skip”

"Sometimes it's just easier to put it all on a skip, although I'm pleased to say that won't happen with our garden."

Sponsors usually foot the bill for deconstruction and relocation - which can amount to £50,000 - but the unwelcome task of taking apart a garden falls to the designers.

"The breakdown of a Chelsea show garden is one of the biggest headaches a designer can have," says Robin Wallis, director of Hortus Loci, a wholesale nursery that supplies many of the Chelsea designers.

"The trouble begins when you have to lift out mature trees, up to 12 metres tall. Their root balls must stay intact and moving them is a fine art." Especially when trees can cost up to £11,000.

Getting 40-tonne lorries in and out of Chelsea is in itself a task, meaning the RHS has strict rules for the deconstruction process.

There is a non-negotiable deadline and exhibitors must gain a clearance certificate before leaving the showground.

Cranes, excavators and skip-loaders are provided, but available slots are limited. They can only be booked two days in advance and there is a race to secure equipment.

But what happens to the hundreds of tonnes of discarded plant matter, soil, compost, gravel, stone, tarmac, concrete and packaging?

The 2012 RHS reuse initiative is supported by Groundwork UK, a charity dedicated to regenerating the country's green spaces with reclaimed materials.

Graham Parry, director of youth employment and skills, describes Groundwork UK's part in the 2012 Chelsea breakdown as "a massive undertaking with an element of the experimental", as it tries to bring the volume of waste as close to zero as possible.

The 2011 Homebase Garden, designed by Thomas Hoblyn, has been donated to the Eden Project in Cornwall.

The garden is very appropriate for Eden. It is cut and carved granite made from a Cornish quarry, replete with a classic collection of Cornish plants.

The garden elements have been in storage with the Hertfordshire company that originally built the garden, until it was moved to the Eden Project.

The public will be encouraged to walk into it and interact with it - people can paddle in the pool.

Over three days, infrastructure giant FM Conway will supply five workers, four 26-tonne trucks with hydraulic cranes and a forklift to transport 400 tonnes of Chelsea waste, costing thousands of pounds.

"The Chelsea breakdown is a very tight timescale, and I estimate that we can re-use or recycle 95% of waste this year. That figure could be 100%, if we could manage the logistics."

Many of the leftover Chelsea garden materials will be used as part of an Olympic legacy programme to deliver 50 community gardens across host boroughs.

These will regenerate community spaces and provide qualifications for volunteer trainees, who are mainly young unemployed people from the recipient communities.