Wayne Rudolf Winterrowd (October 29, 1941 – September 17, 2010) was an American gardening expert and designer who wrote extensively on the subject.
 The garden covering 7 acres at his Vermont home became a tourist attraction to visitors from around the world.
Sir Roderic Victor "Roddy" Llewellyn, 5th Baronet (born 9 October 1947) is a British baronet and gardening expert.
 Despite his lengthy career as a landscape gardener, gardening journalist, author, and television presenter, he is generally best known for his eight-year relationship with Princess Margaret, Countess of Snowdon, the younger sister of Queen Elizabeth II.
Alvilde Lees-Milne (née Bridges; formerly Viscountess Chaplin) (1909–1994) was a British gardening and landscape expert.
BBC Gardeners' World is a monthly British gardening magazine owned by Immediate Media Company, containing tips for gardening from past and current presenters of the television series "Gardeners' World".
James Shirley Hibberd (1825 – 16 November 1890) was one of the most popular and successful gardening writers of the Victorian era.
 He was a best-selling editor of three gardening magazines, including "Amateur Gardening", the only nineteenth century gardening magazine still being published today.
 He wrote over a dozen books on gardening and several more on natural history and related subjects.
 He promoted town gardening, aquariums, bee-keeping, vegetarianism, water recycling, environmental conservation and the prevention of cruelty to animals and birds, all before they were taken up as 'causes' in the twentieth century.
 Most important of all, he taught and promoted amateur gardening before it was acceptable among the gardening establishment, and helped to found the whole consumer industry in amateur gardening that we have today.
Marion Evans (born Marion Jones, 20 June 1935 in Rhymney, Monmouthshire), is a Welsh historian and writer.
 She has written extensively about the town of Rhymney and its neighbouring villages and supporting forewords to her publications have been written by Ted Rowlands, Baron Rowlands; George Thomas, 1st Viscount Tonypandy; Eirene White, Baroness White of Rhymney; Roy Noble, BBC Wales; Edwina Hart, Welsh Assembly Minister and Sir Roddy Llewellyn.
Charlotte Elouise "Charlie" Dimmock (born 10 August 1966) is an English gardening expert and TV presenter.
 She was one of the team on "Ground Force", a BBC gardening makeover programme.
Patti Moreno, born in New York City, is an independent film producer and television personality best known for her work as Garden Girl on the hit web video series Garden Girl TV.
 Living and working in Boston, Patti published the hit website and e-newsletter "Urban Sustainable Living" from 2007-2011.
 Her goal is to pioneer the idea of gardening in small or urban environments, and to inspire and educate people everywhere to grow their own organic food and live sustainably.
 She is also the co-host of Growing a Greener World, author for "Fine Gardening", and gardening expert for HGTV.
David Gerald Hessayon (born 1928) is a British author and botanist of Cypriot descent who is known for a best-selling series of gardening manuals known as the "Expert Guides" under his title Dr. D. G. Hessayon.
 The series started in 1958 with "Be Your Own Gardening Expert" and in 2008 it celebrated its 50th anniversary and the 50 millionth copy in print.
 They have become the best selling gardening books in history.
Nigel Colborn is a British TV presenter and gardening expert/writer.
 He is a former presenter of the long running BBC Gardeners World.
 He is often a panelist on BBC Radio 4’s Gardeners Question Time and is a regular presenter of Granada TV’s Gorgeous Gardens.

Question: What British gardening expert wrote a supporting foreword for a publication by Marion Evans?
Answer: Sir Roderic Victor "Roddy" Llewellyn