An "army" of gardeners spurred on by The Royal Horticultural Society (RHS) has added 22 million plants to gardens in the last year, a survey for the organisation suggests.
The poll of 2,000 RHS members found gardeners typically put in some 10 to 40 new plants a year, which the charity said benefits wildlife, the environment, health and well-being.
It is expanding its "greening grey Britain" campaign, which aimed to promote more planting in concreted and paved spaces, into a "greening Great Britain" scheme to promote growing more plants in any setting.
The RHS said that among the estimated 22 million plants going in the ground or pots a year, at least 157,000 trees were introduced.
RHS director-general Sue Biggs said: "We know most of our members are active gardeners, but these figures are stunning and exceeded our expectations with the amount, and diversity, of plants they are adding each year.
"This is immensely positive for wildlife, the environment and numerous other benefits, including cooling local areas in summer, flood protection, air quality improvement, noise reduction and well-being benefits."
And she said: "Without the plants our gardeners grow we would have fewer insects, wildlife, bees, beauty and benefits to the environment.
"We would have less nature, seasonality and colour in our front and back gardens; and if we didn't have our 'army of gardeners' we wouldn't have the rich and beautiful diversity we are so famed for and so good at maintaining."
The polling by SurveyMonkey also suggests that three-quarters (77 percent) of gardeners quizzed choose plants for bees, while 96 percent of members believe in the health benefits of gardening and 95 percent think it is beneficial for the environment.
Emily Beament is environment correspondent for the Press Association.