A proposal to cut down trees planted in memory of loved ones would be an “act of vandalism”, families have said.
Jo Sweeting paid £200 to plant a horse chestnut tree 17 years ago in memory of her mother and said she had hoped it would live through several generations.
Brighton and Hove City Council wants to remove up to 76 trees at Stanmer Park as part of a project to restore it to how it looked in the 18th Century.
The council said nine trees would be relocated and 250 new trees planted.
It has applied for Heritage Lottery funding to restore the parkland and is waiting to hear if it has been successful.
Many of the trees under threat of removal have been adorned with white ribbons by volunteers seeking to draw attention to them.
George Sweeting said the tree planted in memory of his grandmother, Joy Towner, who died aged 58, was “a constant and living reminder of who my nanna was as a person”.
“The idea of it having to be cut down is devastating,” he said.
Gilli Davidson planted a tree 25 years ago in memory of two of her children.
“It’s brought back the losses, and made me think about that again, and think that if the tree goes then how will I remember them?” she said.
The Stanmer Preservation Society said trees were an example of living heritage and there was no reason to fell healthy ones.
In a statement, the council said the 76 trees scheduled for removal included 40 that were “in very poor condition” and up to 14 groups of smaller trees which were mainly self-sown saplings.
It said it was contacting affected families to discuss the proposals.
No trees will be cut down until the autumn.