When the surprised homeowners returned and saw the transformation, there were often tears of joy.
Attracting 12 million viewers at its peak, the show ran for an impressive 12 series from 1997 to 2005. (Although Alan jumped ship in 2002). The team even did a makeover of Nelson Mandela's garden.
Ground Force popularised the use of garden decking, with B&Q revealing sales had risen from £5,000 in 1997 to £16 million in 2001.
Here's what happened next for Alan, Charlie and Tommy.
Charlie Dimmock was warned against not wearing a bra during Ground Force stint
Alan's been married to wife Alison since 1975 and they have two children.
After earning a Diploma in Horticulture, Alan worked at Kew Gardens before moving into gardening journalism.
He started off as a horticulture expert on BBC show Nationwide, then began hosting Gardeners' World in 1996 before launching Ground Force the following year.
Alan announced he was quitting the show in 2001, to the dismay of fans.
Alan hosted his very own afternoon ITV chat show in 2007 with big name celebrity guests, which ran for seven years.
He also presented coverage of the Chelsea Flower Show for an incredible 30 years, from 1983 until 2013.
Last year, he told Wise Living Magazine: "I live in a spot which is beautiful and which I hope I've made more beautiful. Beautifying the earth on whatever scale is the most glorious privilege.
But Alan's back has paid the price for, as he admitted: "I get a bit of backache from 60 years of gardening.”
Building a pond on ITV series Grass Roots led to Charlie's eight year stint on Ground Force.
Nicknamed 'horticultural Viagra,' Charlie's still remembered for her habit of not wearing a bra while gardening.
Speaking to The Independent, she said: "Even now, people will bring it up. It is very silly.
"It was always just for comfort. If you're swinging a sledgehammer, you want to be comfortable! People say, 'Why don't you wear a sports bra?' But those are not the comfiest things in the world."
Charlie, 54, now presents the BBC's Garden Rescue, where she competes with award winning garden designers the Rich brothers to create stunning gardens for people across the UK.
Charlie recently told World of Cruising that she is still in contact with Alan and Tommy:
"I haven't seen them recently, but we're still in contact.," she said.
"Occasionally we chat or bump into each other.
"Tommy teases me that we're getting old now, which is true, but we have loads of happy memories of filming – lots and lots of laughter."
Charlie suffered personal tragedy in 2004 when her mother, Sue Kennedy, and stepfather Rob tragically died in the Boxing Day tsunami while on the island of Phuket in Thailand.
Loveable tradesmen Tommy did the heavy lifting on the show, and was the only one of the original trio who stayed on Ground Force for its entire duration.
He landed the job through a lucky break.
"I got my break into television totally by chance when I was about 40," Tommy told the Express .
"I had no intention of becoming a TV personality but in the mid 1990s, one particular client, a TV producer who lived in Hampstead, who I'd done some building work for, asked me to have a look at a pilot she was working on.
"She was keen for me to consider a role on the show, but I wasn't convinced at all. Eventually one of my daughters persuaded me to have a go."
While Ground Force ended in 2005, Tommy went on to host several TV shows of his own.
These included Cowboys and Angels, Challenge Tommy Walsh, Tommy's Ultimate Workshop, Tommy's DIY Survival, Tommy Walsh's Eco House and Flip That House with Tommy Walsh.
He also writes DIY and gardening books and has his own DIY brand that was sold in Poundland.
Last year, Tommy joined the presenting team on daytime institution Homes Under The Hammer.
The 64-year-old lives in Hackney with his wife Marie Walsh. They have three children.
In 2013, Tommy opened up on his family's tragic experience of breast cancer and how alarm bells rang when he found two lumps on his chest.
He told The Mirror: "I was being a bit of a bloke about the whole thing. I just buried myself in my work and then went along for the day surgery where the lumps were removed under a general anaesthetic.
"It was only then that it sort of hit me that this could actually be serious and I could have breast cancer, like my relatives.
"Luckily for me, the test results showed that the lumps were benign but it was a bit of a wake-up call about the disease."