The RHS say this year’s Chelsea Flower Show, which opens on Tuesday 23 May, is now a sell-out.

Ticket sales for the show, which is sponsored by M&G Investments, have been the most popular since 2014.

Nick Mattingley, the RHS’s director of shows, said: “Selling out now demonstrates the appetite for the new content and the innovations at Chelsea this year, including the BBC Radio 2 Feel Good Gardens; a ‘secret garden’, which can only be viewed from an elevated position, and an urban street art mural, incorporating plants and art.

“It’s going to feel like a very fresh, pioneering and exciting RHS Chelsea Flower Show.”

For the first time visitors will be offered an elevated view of a ‘secret garden’. The edge of the Linklaters Garden for Maggie’s is a three-metre high hornbeam hedge, which contains gaps where you can glimpse a beautiful garden. The only full view comes from a raised position at the back, which, for the first time, visitors will be able to walk along.

The Chengdu Silk Road Garden combines architecture and planting. Huge multi-coloured sculptural fins representing a Chinese mountain range create an extraordinary spectacle. The Bermuda Triangle features an erupting volcano – another first at Chelsea. A palm at the centre of the volcano erupts from four sections of laser cut aluminium sheeting illuminated by purple and red LED lightings, while a Perspex sheet surrounding the garden mirrors the whole design.

More new sights for RHS Chelsea will be found in The M&G Garden 2017, which is situated within a Maltese quarry, with two giant Maltese lime stone pillars, some eight metres and five metres high. With special permission from the Maltese government, the garden will feature some unusual and specific plants that are unique to Malta - Euphorbia melitensis, Salsola melitensis, Limonium melitense, Matthiola incana subsp. melitensis.

New content this year also includes the five BBC Radio 2 Feel Good Gardens, which will show how plants can enrich and indulge one of the five senses – touch, taste, smell, sight and sound.

Light-emitting concrete, made up of 80,000 fibre optic cords to allow light to shine through it, in Kate Gould’s multi-tiered ‘City Living’ urban garden and a transparent wall made with metallic rods as high as a double decker bus (4m) are two of the urban and cutting edge enterprises at Chelsea this year. Street Art will also feature for the first time in the metropolitan RHS Greening Grey Britain Garden.

Chelsea  attracts around 165,000 visitors.