The couple maintain the plants with the help of their 11-year-old son Charlie, who will start at Chiltern Edge School next month.
The competition, which is organised by the Chiltern Edge Horticultural Society, is judged by a team of five people at the end of July when the gardens are at their best.
Mr Horne, 49, a house husband, said: “Diane and I both come from families that love gardening.
“When we moved here nine years ago we fell in love with the road, then started doing the garden and adding to it every year.”
Last year, Miss Hughes pointed out that when they looked out of the living room window all they could see was a brick wall as the pots were on the ground.
Mr Horne said: “I thought, ‘we can do something about that’.
“We had some old decking in the garden which I kept on top of the garage so I used it to build planters. I’m trained as a builder, carpenter and plasterer.”
The planters were filled with flowers that could be seen through the living room window.
This resulted in the couple being entered into last year’s competition anonymously by someone who called judge Maureen Stevens and they came second.
Mr Horne has done minimal work in the back garden this year as he is waiting for planning permission to extend the family’s home.
However, Charlie has been growing strawberries and Mr Horne has some tomato plants.
Charlie said: “I decided to grow some strawberries as they’re my favourite fruit and I wanted to see if I could grow them myself and see if I could make them like they do in the shops.
“It’s just good to be out of the house and in the sun. Dad waters the plants with the hose and squirts it everywhere and I run around in it!”
The judges had to assess the entries on “wow” factor, design, general tidiness and colour. Mrs Stevens, of Inglewood Close, said Mr Horne and Miss Hughes’s garden was the clear winner.
“I walked up to it and just thought ‘wow’,” she said. “It’s not just the first impression — we all gave it marks out of 10 in the four categories. Obviously Anthony did very well.”
Mr Horne dedicated the award to his parents, Goldie and Teddy, and his partner’s father, Ray Godwin.
He added: “I also want to dedicate it to George Wilks, who lived across the road from me. He was a lovely man who is sadly missed. He was like a grandfather to Charlie.
“He was very well known in the village for his brickwork and flintwork.”
Sixteen gardens were entered for the competition.
The runners-up were Carol and Roger Parker, of Woodlands Road, who won the competition in 2011, and third place went to Margaret Moola and Elaine Williams, of Sedgefield Close.
Mrs Parker, who has lived in the village since 1970, said the couple looked after their garden for enjoyment.
She said: “We don’t ever do it thinking about winning Â competitions but we have won first prize in this competition before. We both like gardening. The garden isn’t that big and has three young trees and a hedge that my husband keeps trimmed at about a foot high.
“Roger is also so proud of his grass, which he maintains himself.”
Mr Parker, 74, who used to be sales director at Sonning Common Garage, added: “I like gardening because it gets you out in the fresh air. It gives me joy to do it.Â
“I try toÂ make sure the back and front look attractive and tidy all the time.”
Ms Moola said: “Gardening is something I do because I love it. I don’t do it for any other reason.Â
“The garden has lots of variety. There’s lots of things in pots because it’s a narrow garden. I have windowboxes that are overflowing with petunias and geraniums.
“I also grow my own vegetables in the back garden.”
The Chiltern Edge Horticultural Society’s autumn show will take place at Chiltern Edge School in Reades Lane on September 3 from 2.30pm to 4.30pm (free admission).
Classes include flowers, floral art, fruit and vegetables, domestic, handicraft, children’s classes and photography.
Entries are required by Wednesday, August 31. For more information, visit www.cehs.info