Chelsea Flower Show visited by the Queen
The Queen and Duke of Edinburgh have toured the Chelsea Flower Show as the event celebrates its centenary year.
Prince Charles and the Duchess of Cornwall also viewed the gardens - including an African-themed plot created by Prince Harry's charity.
More than 165,000 visitors are expected to visit the show in the grounds of the Royal Hospital Chelsea this week after it opens to the public on Tuesday.
Guests of the Royal Horticultural Society previewed the show earlier.
The Queen, an annual visitor to the Chelsea Flower Show, was showed around the the Forget-me-not garden by Prince Harry and its designer Jinny Blom.
The garden was built to raise awareness of the work of Harry's Sentebale charity, which supports vulnerable children in Lesotho.
It includes native Lesotho flowers and a contemporary pavilion based on a traditional Basotho roundhouse.
Ms Blom said the garden is intended to represent the mountainous landscape of Lesotho as well as its people.
She said Harry had been "passionately" involved in the design process and preliminary drawings were sent to him for approval while he was serving in Afghanistan.
Among the early visitors admiring Ms Blom's creation was the prince's cousin, Zara Phillips.
The Queen was also shown the Trailfinders Australian garden, which features a pine and aluminium studio made in the shape of native Australian flower the waratah, and took time to speak to designers Patrick and Sarah Collins in their First Touch garden.
More than 500 exhibitors spent the weekend finishing the 15 show gardens, 19 smaller gardens and 150 exhibits.
This year's displays heavily feature native British plants and the Royal Horticultural Society said it was hoping to inspire young people to start gardening.
RHS director general Sue Biggs described the show as "a plantsman's Chelsea... a Chelsea for people who love plants".
Organisers have also temporarily lifted a ban on the inclusion of garden gnomes as part of the centenary celebrations.
More than 100 gnomes decorated by celebrities including Sir Elton John, Dame Helen Mirren, Lilly Allen, Julian Fellowes and Dolly Parton will be auctioned for the RHS Campaign for School Gardening charity.
Celebrity chef Jamie Oliver, Olympic gold medal winning cyclist Victoria Pendleton and actresses Emilia Fox and Joanna Lumley were also seen admiring the displays.
Beatles drummer Ringo Starr and model Jerry Hall, both regular visitors to Chelsea, were also in attendance.
Former England cricketer captain Michael Vaughan visited his friend Jamie Dunstan's garden As Nature Intended.
"This is my first Chelsea," he said. "I expected it to be big, but it's absolutely spectacular. I'm not a huge gardener but I know when I see something special."
Meanwhile, a report on strengthening biosecurity at UK borders was unveiled at the show by a task force convened by Environment Secretary Owen Patterson.
Mr Paterson also announced that imports of sweet chestnut trees could be banned under proposals to prevent a repeat of the ash dieback crisis threatening ash trees across the country. Sweet chestnut blight is currently afflicting trees in France and other areas.