The team at William Sinclair has raised the funds for Greenfingers by donating two pence from every 20 litre bag of J. Arthur Bower’s Top Soil sold since April 2010.
Retail MD Danny Adamson said: "We wanted to support a charity that has close links to our work and as Greenfingers is a charity dedicated to creating magical gardens at children’s hospices across the UK, we thought it was the perfect partnership.
"We have raised more money than we ever thought possible for Greenfingers. It is close to £20,000 this year.
"Our retail partners have relished the opportunity to support the cause through the top soil promotion and this has delivered the bulk of the funds raised. It has also brought the charity to the attention of thousands of gardeners."
Adamson added: "As well as raising funds from the top soil this year we also raised more than £2,000 at the Garden Industry Manufacturers’ Association’s (GIMA) Charity Golf Day in June and the annual Greenfingers Dragon Boat Race in July.
"We had great fun with our colleagues and customers at the Golf Day and the Dragon Boat Race. For the latter, everyone from our chief executive to factory staff participated and we were all well supported by our families and friends, both financially and on the river banks.
"Everyone at William Sinclair really enjoys supporting the charity and it’s great for morale and team building. We look forward to working with Greenfingers again in 2011."
Greenfingers marketing director Deborah Skillicorn said: "We are delighted William Sinclair has raised so much money for us through the top soil product.
"The team is really positive about fundraising and has a great time doing so. We’d like to thank everyone at William Sinclair for their continued support."