Philip Jarrett said that some secondary staff who had to choose novels for the class to study as a group were spending up to 10 weeks on a single text, with the result that too many pupils lost interest.
His comments follow a study by the Office for Standards in Education of the work of 25 schools to encourage pupils to read more widely.
Mr Jarrett, subject adviser for English at Ofsted, told a London conference on reading: "In discussions, and often unprompted, pupils said: 'Why do English teachers choose such boring books?'
"Their comments may be something to do with the choice of books and the extent to which they challenge pupils, but it's also critically to do with the ways in which teachers work on them.
"Sometimes, by the 10th week they are studying it, pupils have not got the slightest interest in that author, so any drive to go and read more books by that author may have been lost."
Mr Jarrett said that schemes of work introduced in recent years had encouraged the teaching of a much wider range of writing in secondary schools, from poems to a variety of non-fiction.
This, though a welcome development, left less time to concentrate on novels, he said. As a result, some teachers would teach just one novel a year in depth.
Mr Jarrett refused to say which novels were particular turn-offs to youngsters. There was no maximum amount of time he would advise spending on a book and 10 weeks could be appropriate if lessons were good.
The study of whole texts in secondary schools too rarely had a positive impact on pupils' reading outside school, the study found, although there was good practice to be found.
Despite this, it found that a high proportion of youngsters claimed to enjoy reading and that they, and their parents, recognised its value.
Children's books 37