National gardening campaign Cultivation Street has attracted the support of Kew Gardens and The Princes Foundation for Building Community.
Major backers from the horticulture industry have also supported the contest with a string of UK garden centre giants lending their assistance.
The community gardening campaign – now in its third year – is sponsored by the Horticultural Trades Association with national media partner the Sunday People.
Launched by TV gardener David Domoney in 2013 and offering ?20,000 of National Garden Gift Vouchers annually in prizes, Cultivation Street has attracted thousands of entries from across the country.
This year is set to be the most successful yet, with record numbers of entries and the heavyweight support of garden centre giants Dobbies, Squires, Haskins, Strikes, Notcutts, Frosts and Hillview.
Each of the centres is displaying prominent Cultivation Street signage, entry forms and offering advice and planting information alongside their usual service.
This year, Philip Turvil, Grow Wild programme manager at the Royal Botanic Gardens, Kew, will be helping to judge the Pollination Street category ? a new ?500 award for the best community garden aimed at wildlife.
Turvil said: ?I?m delighted to be taking part in the judging for the Cultivation Street campaign ? it?s a brilliant way of encouraging community gardening at all levels across the UK.
?I?m especially happy that the Grow Wild programme is backing Pollination Street ? promoting wildlife at a local level is something we can all support.
?I know there?s a huge amount of creativity and enthusiasm out there and I?m looking forward to seeing the entries.?
Simon Sadinsky, education manager for The Prince?s Foundation for Building Community will judge the Sustainability & Community category for the gardening project most in tune with natural harmony and sustainability via recycling, sustainable planting and timeless skills like dry stone walling.
Sadinsky added: ?Green spaces play an important role in bringing communities together and creating beautiful, harmonious places.
?We believe that engaging communities in creating sustainable open spaces can make a huge difference both to the environment and local residents, particularly in our urban areas.?