Native plants, rewilding designs, sustainability features and even a melting ice sculpture will be among the highlights, says Hannah Stephenson.

The horticultural showstopper of the year, RHS Chelsea Flower Show, is almost here - returning to its usual May slot, after last year's event in September.

Billed as "the world's greatest flower show" the extravaganza will run from May 24 to 28, drawing gardeners from far afield to London to admire stunning garden designs and floral displays.

This year the show gardens are going wild for native plants, naturalistic designs, sustainability, mental health themes, climate change warnings and diversity messages.

Featuring 39 show gardens including 13 show gardens, 12 sanctuary gardens, nine balcony and container gardens and a new category All About Plants in the Great Pavilion, plus four installations to celebrate the Platinum Jubilee, there will be so much to see.

Here are some of the highlights you won't want to miss.

1. Giant melting ice cube

A huge 3m high and wide, 15-tonne ice cube will melt slowly over the five days of the show as a representation of climate change, in The Plantman's Ice Garden sanctuary garden. Representing a clock ticking for the Arctic, the ice cube will reveal a Doomsday Clock at the centre as it melts. Surrounded by verdant Siberian woodland plants, this garden, designed by John Warland, serves as a reminder of the threat that must be addressed.

2. Wellbeing wonder

Check out the swim spa, outdoor gym and yoga area in Kate Gould's Out Of The Shadows sanctuary garden - a lush, tropical-looking creation featuring palm trees, bamboo, false pepper trees and ferns and a subtle muted palette of whites, blues and pinks.

Then there's The Mind Garden, Chelsea gold medal winner Andy Sturgeon's garden for the mental health charity Mind, designed to encourage people to sit, share and listen. It uses tactile additions including water features, oak and clay, as well as natural woodland and colourful meadow planting. At its highest point, it features a circular seating area, creating a sanctuary for conversation.

3. Zen space

An impressive wooden water wheel takes centre stage in designer Yoshihiro Tamura's Circle Of Life sanctuary garden, a city respite in which the wheel symbolises nature's circle of life and flows to a human landscape with fluctuating heights and bending curves, reminiscent of life's ups, downs, twists, and turns.

4. Jubilee tribute

A floral sculptural portrait of the Queen will be among the tributes in celebration of her Platinum Jubilee, created by renowned florist Simon Lycett. This special silhouette of the monarch will be made in the official Platinum Jubilee shade of purple.

5. Textile treats

Ever dyed you own clothes? A Textile Garden for Fashion Revolution from designer Lottie Delamain solely features plants which can be used to make or dye our clothes, in the new All About Plants category in the Great Pavilion. It aims to re-establish the connection between plants and textiles and challenge the impact of the fast fashion industry.

Meanwhile, think wallpaper design and you have a garden setting in the Morris & Co show garden, designed by award-winning designer Ruth Willmott and inspired by William Morris's iconic textile designs of nature and flowers in the late 1800s. At its centre is an intricate hand-crafted metal pavilion with posts and screens layered with two contrasting colours, like Morris' prints, while planting of earthy reds and apricots accented with whites, blues and greens reflect his love of colour and pattern.

6. Bee bonanza

An eye-catching silhouette of a bee wing which forms the centrepiece of the BBC Studios Our Green Planet & RHS Bee Garden is likely to create a buzz this year. Designer and TV gardener Joe Swift has created this one, aimed at inspiring garden lovers to play their part in balancing our ecosystems through planting more species that sustain bees.

7. Foraging fun

If foraging is your bag, the Alder Hey Urban Foraging Station, designed by brothers Howard and Hugh Miller, is one to explore through a landscape of blossoming hedgerows, crab apples and a Crataegus tunnel and other native plants. Don't miss the concrete 'strands' picnic blanket and foraging kitchen.

8. High and mighty

Dominated by a tall, imposing, wood-based panel construction inspired by natural vertical rock strata topped with a green sloping roof and a waterfall cascading to a pool below, you can't miss the Medite Smartply Building the Future garden created by award-winning designer Sarah Eberle. It's designed with a nod to the future of sustainable landscapes and features damp-loving rare and wild species of flora.

9. Sunset strip

There will be plenty of big ideas for small spaces, with nine balcony and container gardens at this year's show. Anyone with a balcony will be blown away by the rainbow colours of The Cirrus Garden, which takes its inspiration from clouds as they take on reds, yellows and purples during sunrise and sunset. The small space is packed with wildflowers, perennials, herbs, a seating area, a vegetable garden and a fish pond to fertilise the garden. Designer Jason Williams had his own 18th floor balcony garden for two years, so he knows what can be achieved in a small space.

10. Gardens for good causes

Some 25 gardens will live on after the show ends, as they are moved to community spaces across the country. A school in London will receive the Place2Be Securing Tomorrow Garden; the New Blue Peter garden will go to RHS Bridgewater in Manchester and The Stitchers' Garden is being adapted for a prison in Suffolk.

Grow2Know's Hands Off Mangrove show garden draws on the story of the Mangrove Nine group who fought for racial justice in their local community and features a 4m high steel mangrove sculpture with nine main roots honouring each 'Mangrove Nine' member. The garden marks the debut of 25-year-old Tayshan Hayden-Smith and his friend, designer Danny Clarke. The steel structure creates a protective canopy, under which communities can gather, sit and reconnect with each other and nature and is to be relocated after the show.

Chelsea Flower Show takes place at the Royal Hospital, Chelsea, from May 24-28. For details visit rhs.org.uk