David Hessayon, who has died aged 96, was a chemist who became the world’s most successful gardening writer. His no-nonsense, populist Expert guides are jam-packed with information and were produced to his own design: instructive text supported by deftly organised charts, pictures and diagrams. Hessayon once said that people were not interested in reading about gardening: “What they are interested in is finding answers to a problem.”
His formula, which achieved sales of 50 million copies over 50 years, hardly changed. His first book, under the name Dr DG Hessayon, was Be Your Own Gardening Expert. Published in 1959, it sold 5.7 million copies in half a century (its original cover showed a man with pipe and hoe, and woman with apron and basket). Be Your Own House Plant Expert (1960) was reckoned to be the bestselling reference book of all time after the Bible, which, as Hessayon pointed out, “had a head start” on him. This was followed by Be Your Own Lawn Expert (1962), Be Your Own Rose Expert (1964) and many others. In 2006, The Vegetable and Herb Expert was Britain’s bestselling gardening paperback, and eight of the top 10 gardening titles of that year came from his Expert series.
Hessayon set no trends, nor did he follow them, although he certainly benefited from the waves of interest in gardening from the mid-20th century onwards. His popularity endured from an age of floribunda roses and snapdragons to an era of wild gardening and celebrity TV gardeners.
None of his success was on the back of celebrity exposure. He never appeared on television or attended book signings. He believed the books spoke for themselves and anyhow: “I’m far too round, far too short, and far too fat, for a start. I didn’t want people coming up to me asking for an autograph or a photograph or a donation,” he told the Guardian in 1999.
Hessayon was born in Salford, Manchester, into a poor family. His father, Jack, an immigrant watchmaker from Cyprus, brought up his seven children – of whom David was the youngest – after his wife, Lena, died when David was very young. He was educated at Salford grammar school and Leeds University, where he studied botany and chemistry – Jack, a passionate gardener, had introduced his son to the plants he tended in the family’s tiny front garden.
Graduating with a BSc in 1950, Hessayon went on to complete a PhD in soil ecology at Manchester University in 1954. Before that, he worked as a journalist in the US, on a Missouri newspaper (where he met Joan Parker Gray, whom he married in 1951 - she was the daughter of the owner) and taught soil sciences at the then University College of the Gold Coast (now the University of Ghana).
He decided, however, that he had no love for the academic life, and in 1955, became technical manager of Pan Britannica Industries, a producer of garden chemicals (including Baby Bio – “the original houseplant feed, for greener leaves and vibrant colours”) based in East Anglia. He remained with PBI all his working life, becoming managing director (1964-91) and chairman (1972-93), retiring in that year when the company was sold to the Japanese Sumitomo Corporation.
Hessayon was, therefore, well placed to write about plants. Indeed, his company became and, until 1991, remained his publisher. In the late 1950s he told his boss he had an idea for a gardening manual and asked if PBI would publish it; his boss demurred but Hessayon said he would pay the company back if it proved a failure. A mention in the Sunday Times for the 36-page guide at 1s/6d a copy brought sackloads of orders.
It was desktop self-publishing before its time: not only did Hessayon write the text – filling the space around the pictures and diagrams in what he called “the holes” – he was also designer, production, sales and marketing manager. “I’m writing with words that a 14-year-old can understand,” he told the New York Times in 1987, explaining that he conducted test-runs of his books with local secondary school students.
The result of this approach was not to everyone’s taste but even the snootiest garden writer recognised his effectiveness. As one reviewer wrote: “His book is not the sort I would ever dream of having at my bedside at night, but I love to have it in the morning when something’s gone wrong with one of the plants.”
Hessayon was also forthright in his views on environmentalists. He was chairman of British Agrochemicals (1980-81), and in that capacity once wrote to the Guardian letters page damning the “witch-hunters” (mainly “greens” and trade unionists) who spoke out against the pesticide 245-T. Hessayon argued that Britain had “dragged itself out of the mire of 19th-century unrelieved pain and untimely deaths by the use of chemical technology”. His books recommended pesticides, but always suggested alternatives for those who did not wish to use chemicals. Later, he softened his views with books such as The Green Garden Expert (2009).
He was proud that his books never disclosed his prejudices, at least in regard to plant choices. However, the original introduction of The Rose Expert perhaps offered a clue to where his affections lay. “The purpose of this book is to show you how to choose, plant and care for the fairest of all flowers.”
After retirement, he and Joan moved to a Georgian home in Halstead, Essex, with 20 acres of land, where he created a series of garden “rooms” in different styles, including a much-loved rose garden.
He did not mention gardening among his interests in Who’s Who. Over the years, those were American folk music, cartophily (the collection of cigarette cards, which had originally inspired his commitment to cramming much information into tight spots) and the Times crossword.
He continued to work and innovate: there was a brand-new series of non-gardening “Expert” books, beginning with The Cat Expert (2010), with Hessayon as a consultant in charge of the layout. He won the RHS Veitch Gold Memorial medal in 1992. When he was appointed OBE in 2007, he said he was pleased that his books had continued to sell despite shifting fashions. Hessayon never wanted them to be coffee-table books; he wanted them to be earth-scuffed and well used.
Joan, a historical novelist, died in 2001. He is survived by their two daughters, Angelina and Jackie, four grandchildren, and four great-grandchildren.
• David Gerald Hessayon, chemist and writer, born 13 February 1928; died 16 January 2025
