But it is his exuberance and energy that typify his BBC television series Grow Your Own Drugs, which explores how to use plants to create natural remedies for everyday ailments.

With a second Chelsea show garden around the corner and another book and TV series out next month, Wong's boundless enthusiasm can only be a boon.

He is all about bringing the science of plants and people to the masses — and attempting to shatter the ivory tower illusion that surrounds much of the discipline. "It is a different take on horticulture," he explains.

In 2006, Wong visited Chelsea Flower Show for the first time with his friend, agricultural engineer David Cubero. The pair — who worked together at Botanic Gardens Conservation International before setting up their firm Amphibian Designs — were struck with the gardens they saw and immediately began planning their own.

Their Burgbad Sanctuary garden at Hampton Court in 2008 was the result, followed the next year by a garden for the Canary Islands Tourist Board at Chelsea.

"We initially started off with this idea of a small garden at Chelsea, then had a huge one at Hampton Court," laughs Wong, who was born in London to a Malaysian father and British mother but spent a large portion of his formative years living in Singapore and Malaysia.

"There was a lot of work involved and David [Cubero] had given up his job so there was a point when it could have all been a big waste of time."

Gaining silver medals at Hampton Court then Chelsea has spurred the team on and Wong is now intent on ensuring that this year's attempt tops the previous entries.

Tourism Malaysia has stumped up the cash for the garden, which is inspired by traditional village lifestyles. "It is not a £500,000 budget but it is quite large," reveals Wong, who will work with Mark Gregory's Landform Consultants team to build the courtyard-style garden.

For Wong, the garden will not just be about great design, but also raising the profile of the profession within Malaysia. "Garden design isn't really considered a career in Malaysia," he laments.

"It is seen as a very low-status job but there is a minister who wants to set up the equivalent of the RHS there and she is very keen on changing people's ideas about horticulture. When I was growing up I told my dad I wanted to be a gardener, and it didn't go down very well."

The garden, which is envisioned as the courtyard of an urban residence in Kuala Lumpur, will contrast terraces of hard landscaping with swathes of wild, naturalistic planting. The scheme's planting will use species iconic of traditional Malaysian gardens, most of which are usually considered purely edible crops. These include fruiting banana trees and mature coconut palms, underplanted with yams, gingers and lemongrass.

"The idea of the show garden is not only to attract tourists to Malaysia but to show residents the value of the indigenous plants so they are not cutting down virgin cloud forests to plant things like tulips," explains Wong.

"Where I grew up, gardening books were always European or from the US, and that was what a good garden was considered to be — that perfect square of lawn with this suburban English look.

"But you can't really reproduce that in Malaysia and you end up digging out incredibly rare and beautiful local plants. We are trying to highlight the best Malaysia has to offer."

Wong may seem to have had an almost meteoric rise to fame. But, in fact, it has involved a long, hard slog. A presenting role on BBC's Countryfile, filming the second series of Grow Your Own Drugs as well as writing an accompanying book — both due to land on 16 March — and working as a guest lecturer at the University of Kent all mean long hours for Wong.

As the pressure mounts in the countdown to Chelsea, it will require all that passion and enthusiasm to keep him going. "I don't really have days off," says Wong, who scooped the Garden Media Guild award for garden programme TV broadcast of the year in 2009 for Grow Your Own Drugs.

Rumour has it that the BBC may follow Wong during the build of his Chelsea garden, adding even more anxiety to the process. "TV is lots of fun but doing Grow Your Own Drugs you are not in the most stressful situation where your delivery hasn't arrived and a tree has just snapped in two," he adds.

At least Wong can take solace in the fact that he knows how to brew up a cup of valerian hot chocolate, which is ideal for stress.

CV

1999-2003 BSc in business administration, University of Bath

2003-04 Volunteer work in Bristol

2004-06 MSc in ethnobotany, University of Kent and RBG, Kew

2006-08 Media relations officer, Botanic Gardens Conservation International

2008 Hampton Court Palace Flower Show garden, Burgbad Sanctuary

2009 BBC2 Grow Your Own Drugs series begins

2009 RHS Chelsea Flower Show, Canary Islands Spa Garden