LONDON • Britain has a "lost generation" with no gardening skills, the Royal Horticultural Society (RHS) has warned, as its sprawling Chelsea Flower Show got under way with an inauguration by Queen Elizabeth II.

"The lost generation are the ones from their mid-20s to 40s," RHS director-general Sue Biggs was quoted as saying in The Times newspaper on Monday.

"For a lot of them, their parents just didn't teach them gardening and we lost a lot of the skills. What happened to our nation of gardeners?" she asked.

She said she believed the gap in knowledge was because Britons that age were born after it became common for both parents to work, the Telegraph reported on Monday.

She noted that her mother did not work and so had time to teach her about plants and gardens.

A survey by the RHS in 2011 interviewed 500 people from three different generations about their gardening habits, and found that less than 1 per cent of parents were taught gardening in school.

This was in comparison to 55 per cent of grandparents, according to the survey.

A separate survey in the same year showed that more than half of children did not know how broccoli grew, and nearly 80 per cent did not know how to recognise foxgloves, the Telegraph reported.

This year's Chelsea Flower Show in London features a "modern slavery garden" by the show's first black designer, Ms Juliet Sargeant, as well as a garden watered, lit and heated with a mobile phone app and an "acoustic garden" which plays musical notes to visitors.

A field of some 300,000 knitted red poppies was unveiled as a tribute to Britain's war dead.

There is also a 3m-high floral installation created in honour of the Queen's 90th birthday. Made up of 10,000 flowers, it forms a portrait of the monarch.

One of the most talked-about gardens was the Harrods Eccentric British Garden that puts on a performance with mechanical buzzings and whirrings, a tower whose roof rises, shrubs that bob up and down and topiary trees that go round and round, the RHS said.

The society is also using the prestigious event to promote its Greening Grey Britain campaign, warning that too many gardens are being paved over by Britons to make car parking spaces or patios for barbecues.

The number of traditional front gardens that have no vegetation has trebled in the past decade to five million, the RHS said.

Some 160,000 visitors are expected at this year's show, which ends on Saturday.

AGENCE FRANCE-PRESSE, REUTERS