What to look out for: Chelsea Flower Show 2018 exclusive preview

It’s only three days before RHS Chelsea Flower Show 2018 opens its gates and the show site is abuzz.

Rather than floral scents, it’s the beep of reversing lorries and clod of steel-capped boots that fills the air right now, and the brightest colours are of the army of high-vis jackets worn by every visitor.

But look closely and the amazing show gardens and stands are coming to life. Petals are unfurling, paths are being hosed to perfection and it’s almost time for the show.

A fast-flowing beck pours over smooth stones alongside a stone creamery that looks like it’s been there for a couple of hundred years. There are cow pats, bits of sheep wool snagged on the fence and the footpath that climbs beside the stream looks convincingly trodden. Listen carefully and you might hear a curlew call (it’s on audio loop).

This garden is such an evocative slice of the Dales you can almost smell the sheep… which actually you probably can if you look closely at what’s been deposited on the grass.

"In my mind this belongs to a lady farmer, who has diversified to build a creamery making Wensleydale cheese, using the garden to pick flowers and vegetables from the garden to take home," says designer Mark Gregory, about his Welcome to Yorkshire garden, the 97th garden he has built for Chelsea Flower Show and the 5th he has designed.

Every one of the stones used in the stream and dry stone walls came from at the Bolton Estate in Wensleydale and will be returned there after the show.

Tom Stuart-Smith is back at Chelsea after eight years with the magnificent Weston Garden in the Great Pavilion, a forest-like glade in which to wander amid multistem trees and elegant, lush understorey planting.

"The plants are beautiful and it creates a nice feeling," he says modestly, removing his knee pads for a moment from some last minute plant arranging.

This is a waste-free garden. "I got a bit disenchanted with the amount of waste at previous shows so there is no concrete in this garden and almost all the elements from the will be recycled."

Chelsea buffs may recognise some of the trees here from previous show gardens by Christopher Bradley-Hole, Dan Pearson and Luciano Giubbilei. How has the show changed since he was last here?

"I think there’s less off the wall stuff that you can get outraged or amused by. It’s a bit safer, a little more homogenous. There’s lots of tasteful intermingling planting. I rather miss Diarmuid Gavin! You can put plants together to make pretty patterns, but at home would it actually work?"

McBean’s Orchids stand in the Great Pavilion should also be a must-visit, especially now millennials and their house plant zeal have discovered their beguiling ways.

And everyone will want to go home with Oncidium Glyndebourne Abigail ‘New Marquee’.

For nursery owner and orchid breeder Jim Durrant, though, the amazing shapes and colours of his orchids in flower are not as exciting as when they’re in bud and you don’t quite know what will emerge.

"We keep breeding orchids and diversifying their species. They have humans in their control," he says. They are displayed on an eye-catching plaster art installation called ‘Lowing’

Dahlias are most definitely on trend again and the National Collection of Dahlias stand is a showstopper.

John Wheatly has seen the changes. "Dahlias used to be all about bald old men on allotments like me, but what changed it all was the discovery of Magenta Star in New Zealand with dark foliage that we’re using to create loads of exciting new cultivars."

Scroll through the gallery above for a preview of the best of this year's show.