Genealogists and cemetery staff will take visitors on tours, and give talks about burial practices and trends as well as the histories of prominent and fascinating people interred at the west Auckland site.
"I think increasingly New Zealanders are wanting to participate more in planning and even carrying out burials," said Sandra Coney, a member of the Waitakere Ranges Local Board which helped put the open day together.
"It enables people to express their love for that person a great deal, rather than just sanitising it by handing it over to somebody else."
Displays and information will include advice on how to help prepare a loved one for burial, conduct a service and help dig a grave with cemetery staff.
There will be a crematorium tour and demonstrations of natural (eco) and Muslim burial practices.
Waikumete is one of two cemeteries in the Auckland region to provide for Muslim burials and the only one to provide for Jewish burials.
Natural burials, carried out in a specialist site for the past year, were becoming increasingly popular, Coney said.
Bodies were not embalmed, and clothes and adornments had to be biodegradable as did caskets. Native forestry was cultivated to mark the site rather than a headstone. "The idea is it eventually becomes a natural forested area," Coney said.
It appealed to people conscious of sustainability and who felt "they're part of nature when they're going back to the soil".
There will be a demonstration of the digging of an eco-grave.
The open day will also allow visitors to learn more about its unique avenues of mausoleums, features usually seen in cemeteries in Europe and America. And also the cemetery's urban urupa, recognising traditional Maori burial practices.
Waikumete was established in 1886. A memorial commemorates the single largest burial site of 1918 influenza pandemic victims in New Zealand, and the Erebus memorial remembers victims of the 1979 fatal air crash in Antarctica.
Stories will be posted beside the graves of 25 people who have a prominent or historically significant past, including three Victoria Cross winners.
Among those buried at Waikumete are superstar musician Pauly Fuemana, legendary motor racer Bruce McLaren, and award-winning writer and playwright Maurice Shadbolt.
Maps will be provided so visitors can locate points of interest. Assistance would also be given to locate loved ones, including in unmarked graves.
"So many Aucklanders have family members buried in Waikumete - which might be several generations back," Coney said.
"So people can come along with just a name. There's genealogists there. Cemetery staff can help people find exactly where a grave is and help them to go and visit it."
The 108-hectare cemetery was also home to one of the largest collections of wildflowers of South African origin in the country. Today's open day was timed to coincide with their flowering, between September and December.
The Glen Eden cemetery had become somewhat of a "wildflower sanctuary", Coney said, with flowers left by graves seeding large areas. "When they're out, they make an absolutely spectacular sight."
Waikumete, one of the largest parks in the Auckland region, was "an open space just as much as it's a cemetery". "It's a place where you can go for walks, and lots of people take their dogs for walks through Waikumete."
Coney, who has three generations of family buried at the cemetery, has bought a plot there for her and her partner.
But there was a pending space crisis, with Waikumete currently only having room for another four years of burials, she said.
Auckland Council manager of cemeteries Catherine Moore told the Herald on Sunday there were two potential solutions to Waikumete nearing capacity.
"The rest of Waikumete Cemetery has a significant ecological area overlay under the Auckland Unitary Plan, however we could apply for a resource consent to develop some of this area," Moore said.
"Alternatively, we could look to find other suitable land to develop another cemetery elsewhere in Auckland. There is no land adjacent to Waikumete Cemetery that can be used, so we do not have the option of extending the cemetery.
"We are currently looking into the feasibility of both options."