"We do have a barbecue each year and invite all locals to come and join with us, but this year will be different," reserve convenor Dougal French said.
Mr French, a former principal of Havelock North High School, said more than 100 people were expected to attend the barbecue, including Hastings Mayor Lawrence Yule and councillors.
Activities will commence at 4pm with a conducted walk through the reserve by Mr French.
He said reserve birdlife was now abundant with tuis, bellbirds, fantails, wood pigeons and moreporks. "It's a true testament to the volunteers who carry out plantings, maintenance and improvements during the week and particularly on Friday mornings," he said.
"It's a great time for the 'Last of the Summer Wine' to get together, have a good sociable work experience and do something for the community."
He is resigning his role as convenor at the Landcare Group AGM next month, but hopes to continue as a committee member.
"I am sure it will continue, so long as the local people continue to rally around it as they have done for 20 years."