Former Beatles drummer Ringo Starr formally opened the event’s WaterAid garden while The Who frontman Roger Daltrey was at the Homebase Teenage Cancer Trust Garden as a patron of the charity.
Daltrey admitted he was not much of a gardener himself. “My garden’s nothing like this. I like it wild.”
Daltrey, who posed for photos with two young cancer patients who have been helped by the trust, told reporters “this garden was actually provided by B&Q”, before being corrected that it was in fact Homebase.
“I just came off a plane from Japan. I’m only halfway here.”
Other famous faces to visit the show included Michael Caine and Cliff Richard, who posed for photos at the Barbados Horticulture Society’s floral display.
The show, which has been held in the grounds of the Royal Chelsea Hospital since 1913, will be open to the public from today but special guests were able to get a sneak preview tomorrow.
Among the mix of traditional, contemporary and wacky garden designs on display was Chelsea regular Diarmuid Gavin’s 24m tall pyramid, which towered over everything around it.
His Westland Magical Garden is made up of scaffolding constructed over eight levels, all covered in greenery but with different themes.
Bellboys will take people up the levels in lifts, with the option of a stainless steel tube to slide back down.
The award-winning TV gardener said: “I’ve experimented with gardening in urban situations, where green space is at a premium.
“We’ve tried to see if different people can have completely different gardens all on top of each other. It’s also a humorous garden as well, as there are lots of fun elements, like the slide.”
Gavin said his favourite level was the second one. “It’s a little Oriental garden, a secret one.”
Gavin, who created the first floating garden at Chelsea last year which dangled from a crane 25m high, said he did not feel like he necessarily had to build upwards again.
“It’s not an obsession. I don’t try and beat anything. If you’re inspired by something, you just go for it. It’s not about trying to outdo what you’ve done before.”
The Irishman said the inspiration behind his creation was the Albert Bridge, which is close to the show’s site.
Other guests included 65 Chelsea pensioners who were pictured on Gavin’s pyramid.
Britain’s Got Talent judge Amanda Holden posed for photos at the L’Occitane Immortelle Garden, which was designed to look like a scene from Provence.
Wearing a pink wraparound Dolce & Gabbana dress and leopard print high heels, she admitted she was not that suitably dressed.