BBC bosses have axed Gardener's World presenter Toby Buckland after three series.
The host is said to be disappointed that he has been dropped to make way for former presenter Monty Don to return.
Monty's reappearance also means the show will change location once more - from Berryfields to the returning host's own garden in Herefordshire.
Toby stepped in to host the show after Don suffered a minor stroke in 2008 and suddenly disappeared from the long-running BBC Two series.
Alys Fowler is also leaving the series, but another former presenter Rachel De Thame will rejoin. Regulars Carol Klein and Joe Swift will return.
Producers of the show announced a back to basics approach of the show last year after a series of changes designed to appeal to casual gardeners alienated more traditional viewers.
Monty joined Gardeners' World in 2003, replacing Alan Titchmarsh, but stepped down in May 2008.
He has spent two decades developing the extensive garden around his home in the Herefordshire countryside. It will be the first time in more than a decade that it has been featured on screen and viewers will be able to watch it evolve at the same time as their own gardens.
Since leaving the show, he has hosted Around The World In 80 Gardens and Mastercrafts for BBC2.
Monty said: "I've really missed the programme so I can't wait to get stuck in and get my hands dirty again."