Part of Britain in Bloom, the panel of judges for South and South East in Bloom, announced the winner from the hundreds of entries at Fareham last week.
Spelthorne Council's Cabinet Member for the environment, Tony Mitchell, thanked the contractor Lotus Landscapes, and the Council's Neighbourhood Services team.
Lotus Landscapes sales head Byron Crofton said: "We had a pretty torrid Spring, when a deluge of rain fought a war on the roses. You are never told when the judges will visit the parks or gardens, so our team, led by Michael Codd, would start mornings at 5am to try and repair the damage from the storms. I'm delighted and relieved that their immense hard work has been recognised by winning the Gold Award along with the overall winner for Small Parks.
"Sunbury Walled Garden is a horticultural gem, with a spectacular range of trees, roses, lavender, lupins and other plants, all contained within a two-acre site. The park is top-rated on Trip Advisor and is an excellent example of how an old and neglected garden can be revived with a combination of council, community and contractor support."
Lotus Landscapes are also the contractors for Sunbury and Staines Cemeteries, which retained their Silver Gilt Award status.