It’s the laugh. It’s an unmistakable laugh. Everyone on Fred. Olsen’s cruise ship Braemar got to know it.

If Charlie Dimmock was giving a talk in the Neptune Lounge, chatting to passengers or relaxing during an evening show, it was her deep laugh first, then her lush red locks, that made her instantly recognisable.

It’s a spontaneous laugh that launched her into the world of television, Charlie told passengers on the Gardens of Madeira and the Canaries cruise.

The girl who worked in a garden centre had helped out on a Meridian TV programme in the 1993 by demonstrating how to build a pond. It was just a favour and nothing came of it until four years later when she received a call asking her attend to a screen test.

Charlie said: “It came completely out of the blue. I had no idea what I was getting into, let alone what to wear.”

Charlie sought advice and decided to wear office clothes to the interview. With her hair tied back, she arrived in London wearing an A-line skirt and cardigan.

At the studio she got into some banter with Tommy Walsh while they were waiting around for the camera tests. Charlie said: “When the producer heard me laugh, I was offered the job. I might have looked like a librarian but they liked my laugh.

“It got me the job.”

That job was on the BBC’s garden makeover programme Ground Force, so away went the librarian look and Charlie was back in her usual dungarees, T-shirt - and no bra.

“It was just the way I was, how I usually dressed,” said Charlie, who trained in horticulture and put comfort first when it came to manual work.

Ground Force took Charlie, Alan Titchmarsh and Tommy Walsh the length and breadth of the country and made the team household names.

Alan was already established in the horticultural world, so he would design a garden for a well-deserving person while Charlie and Tommy would sort out the practicalities so the job could be completed in two days.

Such was the popularity of the show that viewing figures reached 12 million viewers and the series ran for eight years.

The programme took the Ground Force team across the globe, from India to create a garden at a children’s orphanage to a hospital in the Falklands. In USA, they built a garden as part of Bette Midler’s project to buy plots of land in New York and make them accessible to all.

Most magical was building a garden for Nelson Mandela in South Africa, said Charlie. “This was really special - he has a real aurora about him."

Since Ground Force, Charlie has embarked on a variety of challenges. She learned to fly the trapeze at a circus and she confessed there were ‘tears every night’.

In another programme she learned to tango with a troupe half her age. She explained: “I was spray tanned orange and had my hair scraped back. It was dyed black with shoe polish from one of those sponge applicators. Hairspray was applied so thankfully the black did not run.

“I had to be at RHS Chelsea the next day and I was still orange. Fortunately the shoe dye came out easily!”

Charlie’s lectures on Mediterranean plants, container gardening and ponds were so popular that she had to repeat the sessions to accommodate all of the passengers. At the end of every talk there was always a queue to ask the garden expert all sorts of questions from what to do with a wind-scorched cistus to a sick bonsai tree, plus the identification of plants passengers had seen on their travels round the islands.

She also offered tips on what to look out for on each island; on Madeira everyone felt quite the expert pointing out sub-tropical jacaranda trees, various succulents and euphorbias.

In Portugal we kept an eye open for the giant strelitzia.

“It looks similar to the usual bird of paradise flower but the plant is much bigger. The leaves are huge like a palm tree and the flowers are blue with charcoal colouring and pale blue petals,” said Charlie, encouraging her eager audience who off to Lisbon’s botanical garden and the grand Palacio Nationale de Queluz.

By sharing her knowledge and her laughter, the cruise was all the better for her company and she seemed to have good time, enjoying the friendly and casual atmosphere.

She said: “Fred. Olsen cruises are really relaxed so my lectures can be nice and relaxed, too.

“It was great to be in Madeira. I loved it there – everyone on that island must have green fingers!”

Not every passenger on Braemar boasted greenfingers but they were certainly inspired to get back in the garden on their return home.

Charlie also had a gardening list – from cutting the grass to planting seeds. She said: “I’ll look in the greenhouse as soon as I get home and see if the seedlings I put in before the cruise have survived. I reckon they could be dead by now!”

And then there was that laugh again.

FACTFILE: Braemar's M1327, a 13-night cruise that departs from Dover on November 5, 2013 and visits Funchal (Madeira), Santa Cruz (La Palma), Santa Cruz (Tenerife), Arrecife (Lanzarote), Lisbon (Portugal) and Leixoes (for tours to Oporto, Portugal), then returns to Dover. Prices start from £1,149 per person, based on two adults sharing an inside, twin cabin. This price includes all meals and entertainment on board and port taxes. Visit www.fredolsencruises.com or call 0800 0355 150 (Monday – Friday, 8am – 8pm; Saturday, 9am – 5pm; Sunday, 10am – 4pm).