Gardening writer whose no-nonsense Expert guides have remained in the bestseller lists since the 1950s

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.