Like all good legends, the tale of the Tatum family’s annual Father’s Day picnic grows taller in the telling.

Kevin Tatum says this year’s picnic is the 29th; a neighbor insists he can remember attending for 31 years. “No, 33,” interjects another.

According to Kevin, the barbecue draws 300 people each year. Or 500, to hear another relative tell it. A thousand, if you ask a third.

The amount of food expands with repetition, too. Kevin, who bought the food, says this year’s bash required 60 pounds of ribs, 80 pounds of chicken and 240 pounds of trout. Then, John Ta­tum, the patriarch of the family, reports that the family is in fact serving nearly 100 pounds of ribs and 450 pounds of fish, and he can’t begin to count the hot dogs and hamburgers.

What all agree on is this: Come Father’s Day, John, 94, invites five generations of family, everyone in their Michigan Park neighborhood, his church choirmates, his swimming buddies and anyone else who cares to drop in to a backyard barbecue that has become the stuff of lore in his Northeast Washington community.

“We invite everybody,” John says. “We don’t know everybody. But everybody knows us.”

The tradition has its roots in the mid-1980s, when John’s son Rodney remarked after a wake in the neighborhood that it was a shame that the community came together only at funerals. An annual ­father-son softball game was born of that conversation.

As the participants aged, the post-game barbecue became the sole event. (Although John — a Senior Olympics medalist who is headed to his sixth national swim meet next month — wasn’t tuckered out yet, the 60-year-olds a generation younger felt their softball days were over.)

The Father’s Day fest started with a couple of dozen people. Now, it draws relatives from as far away as Washington state and scores of friends, some who have known each other for half a century. So many met at McKinley Technical High School in the 1960s and ’70s that they still introduce themselves by their class years.

But newcomers join the party every time, too. Arnold Murray, who grew up near the Tatums’ house and now lives in Southeast Washington, heard about the event from his brother, so he decided to come by. He walked up to someone cutting raw trout, coating it in bread crumbs and Old Bay seasoning, and passing it along to be fried in one of three pots of oil bubbling over propane-fueled outdoor stoves.

“I asked him if I had to be on the mailing list or something,” Murray said. “He said, ‘No, just come on out.’ ”

The man expertly preparing fish to feed an army was just one of many volunteers Sunday. In the early days, the MVP of the softball game had his name inscribed on a neighborhood trophy each year. Now, that trophy bears the name of each barbecue’s most valuable helper.

John notes that one friend cooked ribs all through Saturday night and into the wee hours of Sunday morning. “This qualifies him greatly,” he says, though the prize is still up for grabs for the cleanup crew.

Guests often donate money to help pay for the food. And the community is grateful for the Ta­tums’ hospitality.

“It’s off-the-chain fun,” says Butch McNair, who has worked one of the four huge coal grills for about 18 years. “Starting tomorrow, I’ll start looking forward to next year.”

Patricia Diggs moved away from the area to Lanham, but she still brought her granddaughter to the picnic. “You don’t have many gatherings like this. We don’t bind together as family and friends as we used to,” she said. After losing her husband in 2002, her brother in November and her son last month, she wanted to be around members of her community, and she knew she would find them at the Tatums’ on Father’s Day.

“It’s just good to be around family and friends and feel that you have people who are watching over you,” she said. “There’s nothing like the neighborhood.”

John said he thinks of the picnic as a memorial to his son Rodney, who started it all. Rodney died more than 20 years ago at age 37 from lung cancer, just a few months after his older sister died of cancer, as well.

This year, John is mourning the recent deaths of his brother and sister. “Some of our best people have passed,” he says, staring out the window of his home in the early hours of the noon-to-night party. He recounts memories of a few volunteers, no longer living, who used to man the grill and the serving line just beyond that window.

Then he seems to stop seeing ghosts of Father’s Days gone by and to focus on the person at the barbecue heating dozens of chicken quarters over the coals. “This is a new man,” he says. “I hope he’s going to stay.”