The university, which leases the land from the city's freemen, said it will not renew the agreement due to the running costs and investment needed. The garden's grounds, desert house and tropical glasshouses hold plant collections amassed over almost a century.
Moorbank education officer Helen Talbot said until the university notifies the landlords in the new year, and the friends know what research and bequeathed plants could be moved, plans to open the site to the public cannot go forward. "We're hoping to negotiate with the freemen a separate lease so the garden can continue as a community resource and public attraction. But our biggest fear is the university will just take everything and leave us nothing but grass."
Newcastle University science faculty pro-vice-chancellor Professor Steve Homans said: "The primary purpose of Moorbank has been to support university teaching and research. However, the level of activity in both of these areas at the gardens has reduced in recent years."
He added: "The number of students using Moorbank is minimal. This has prompted us to review the research, teaching and engagement activities and assess whether they offer value for money.
"The gardens are not attracting those young people we need to reach on the scale we need in order to meet the Government's increasingly challenging widening participation targets.
"We have notified the landowners of our intention to surrender our lease, giving 12 months notice. We would be delighted if the Friends of Moorbank or any other volunteer group wanted to take over the lease."
The university withdrew a ú188,000 Heritage Lottery Fund (HLF) bid in August, but the HLF said it could back a future project with the friends group.