So what can we expect from this year’s horticultural extravaganza?
Maverick designer, Diarmuid Gavin is back and is bound to draw attention with his Harrod’s Eccentric British Garden, inspired by designer Heath Robinson, with swirly topiary and an octagonal folly.
Every 15 minutes, box balls will bob up and down, conical bay trees begin to twirl, and planting will rise from the ground. (See above).
Well-being is a big theme of this year’s show and herb queen and RHS ambassador Jekka McVicar has come up trumps with A Modern Apothecary Garden, promoting food as medicine.
It features heart-strengthening hawthorns, a cobbled path, (which is instant reflexology if you walk on it bare-foot), lavender, rosemary and other well-being stalwarts.
Other gardens along similar lines have been designed by Chris Beardshaw, whose show garden for Morgan Stanley will be relocated to Great Ormond Street Hospital after Chelsea as a therapeutic space for parents.
Anne-Marie Powell is designing the official RHS Greening Grey Britain garden (not a show garden), to support its campaign, featuring bright borders to lift the spirits, benches to relax and share a chat on, soothing water features, a bee-friendly perennial meadow, edible plants in pots and a stylish kitchen garden.
In the Fresh Gardens category, featuring smaller gardens, check out a weird-looking granite cubes surrounded by ashes and charred fencing.
Look through the cracks and you’ll see a mass of planting in The Antithesis of Sarcophagi garden, sponsored by The Marble and Granite Centre.
If you love seeing gardens inspired by foreign places, designer Sarah Eberle is back with an Artisan Garden inspired by the Mekong River in Cambodia.
The 7m x 5m space is entirely water, with a small deck leading to a floating lounger styled on a traditional fishing boat.
Look out for the unique ‘Together We Can’ acoustic garden, developed by Peter Eustance of Symphonic Gardens for disability charity Papworth Trust, inspired by world-famous profoundly deaf percussionist, Dame Evelyn Glennie.
Features include a water marimba which will transform the garden into a musical instrument against the backdrop of a natural woodland copse, interwoven with features that evoke the equipment of a recording studio.
The overall form of the garden will be reminiscent of the structure of the ear.
Ones to watch for this year
* Sam Ovens, winner of the RHS Young Designer of the Year 2014, who hopes to bring heathers back into fashion with his debut Chelsea show garden for Cloudy Bay.
* After 25 years of exhibiting in the floral marquee, Rosy Hardy makes her debut in show gardens with Brewin Dolphin’s Forever Freefolk, inspired by declining chalk streams.
* Tropical plants feature heavily in Catherine MacDonald’s stunning design for Hartley Botanic.
* Twice Best in Show winner, Cleve West, brings visitors a garden inspired by Exmoor Royal.
Visitors will receive a welcome of the highest order as they arrive beneath majestic floral arches designed by Royal florist Shane Connolly to mark the Queen’s 90th birthday, using all-British blooms. There will also be an exhibition of photographs of the Queen’s 51 visits to the show since 1949,
In new plants, Bake-off queen and National Gardens Scheme president Mary Berry will be launching a beautifully fragrant pale lemon hybrid tea rose from Harkness ( www.roses.co.uk ) named after her.
Hillier Nurseries ( www.hillier.co.uk ) will be introducing Lavandula ‘Silver Line’ in aid of The Silver Line charity, founded by Dame Esther Rantzen.
This white variety flowers profusely from late May to August, making it a magnet for bees and butterflies, and has a compact habit (height 25-30cm x spread 25-30cm) perfect for containers, low hedging or the front of a border.
Rose specialist David Austin is also celebrating its 90th year ( www.davidaustinroses.co.uk ), and to celebrate, the company will launch three new English roses.
‘Imogen’ has delicately frilled, soft lemon petals; ‘Bathsheba’, a super fragrant English climbing rose with large flowers and ‘Roald Dahl’, a free-flowering variety with peach coloured flowers, marking the centenary of the birth of the storyteller.
RHS Chelsea Flower Show runs from May 24-28 at the Royal Hospital, Chelsea. For details visit www.rhs.org.uk