The gardening show had been temporarily taken off air during the coronavirus pandemic, and listeners have now been told that it may not return until the next financial year beginning in April 2021.
And it may not be fronted by Tim Crowther, as the popular presenter has revealed that he is no longer under freelance contract at the BBC after over 40 years of service.
Crowther previously hosted the show with the late Joe Maiden - known as Yorkshire's most famous gardening personality. A Facebook page for horticultural advice run by Crowther and Maiden's replacement Graham Porter has over 7,000 followers.
Listeners who contacted the BBC were told that 'rested' programmes from the Sunday schedule would not return until the end of the year at the earliest, and possibly not until 2021.
A statement from Tim Crowther said: "Despite my hopes to the contrary, it would seem that our Sunday mornings together will not return for some time to come. There may be a pre-Christmas review of this decision, but the likely scenario is that the existing four-hour programme formats will remain until the end of this financial year, in April 2021.
"This makes me sad. I miss being on the radio very much, I miss our Sunday mornings together and I actually really miss having a laugh and a giggle with you lot! Earlier today I was looking back at a plaque commemorating 20 years of 'Tim and Joe on BBC Radio Leeds'. With Graham's expertise and unending support, I've now clocked up 27 years of gardening shows for the station! I'm fiercely proud of my 43 years of broadcasting for the station. To see it fizzle out like this is hard, but it's a reflection of the tough times we're all living through.
"I'm now out of contract with the BBC, and so justifying the time I spend managing our Facebook group is increasingly difficult to do. It's a tough call, and I have not yet concluded what I should do. Close the group altogether? Archive it in the hope that our programme returns? Or just keep going for now? The world can change between now and next April. Certainly the group name is no longer relevant.
"I am genuinely pleased that Graham appears, albeit briefly, as part of Andrew Edwards' breakfast show. Let's be thankful for small mercies. Let's keep supporting Graham, Andrew, and BBC Radio Leeds. It's a really great radio station with which I am very proud to be associated."
Fans have even launched a Change.org petition to have Crowther's contract renewed and for the programme's future to be guaranteed. Ann Devine, who began the campaign to collect 500 signatures, said: "I am very saddened to hear the news that Sunday Gardening will not return to its 'normal' format for some time, possibly into the new financial year. I am even more disappointed to hear that the lovely Tim Crowther may not be returning at this point.
"I have grown up listening to BBC Radio Leeds and the gardening programme with Tim and the late Joe Maiden has always been a highlight, and is definitely what sparked my interest in gardening. When Joe sadly passed away, it was like losing a member of our own family and yet Tim stood proud and bravely carried on for the sake of his listeners and followers - a true gentleman and someone Radio Leeds should be proud to have on their presenting team. What an achievement he has of 43 years of service! I'm not sure many others share that accolade.
"Tim has carried on through all challenges and welcomed with open arms our next gardening expert, Graham Porter. Together the pair helped ease our grief for Joe and carry on the excellent advice and enjoyable listening on our Sunday gardening show and continued to gain members on the Facebook page - a valuable resource and wealth of knowledge with now over 7,000 members, definitely something to be proud of.
"My plea is just a small drop in the ocean but I sincerely hope you reconsider your decision to not only end such a great programme but also bring back our wonderful Tim."
Crowther, 61, is originally from Halifax and began working for BBC Radio Leeds while still a student at Leeds College of Music in the late 1970s.
His former presenting partner Maiden was a renowned vegetable-growing expert who lived in Huby, near Harrogate. He died from prostate cancer in 2015.
A BBC spokesperson said: “During the coronavirus pandemic BBC Radio Leeds is broadcasting a streamlined schedule and as part of this Tim Crowther isn’t currently on air. This means we are unable to renew his contract at this particular time but will be staying in touch in case things change. Our gardening expert Graham Porter remains on air on Sunday mornings between 9-10am and continues to offer listeners help and advice.”