Craig Morgan Shares the Ways He and Wife Karen Honor Late Teen Son Jerry: 'He Lives in Our Hearts'

Country singer Craig Morgan lost his 19-year-old son Jerry in a tragic accident six years ago, but has found ways to ensure that the teen's spirit lives on.

Morgan, 58, opens up to PEOPLE in this week's issue about learning to live with his loss, and the many ways in which he and his family remember the late teen, who died in a "freak" boating accident in July 2016.

"Jerry's not here, but he is not gone," Morgan says. "He lives in our hearts and heads and always will."

For one, Morgan and his wife Karen Greer, 54, buried Jerry on their property in Tennessee, right near their family chapel, which also includes a tribute to the star athlete — a 13 in the roof overhang, as it was his favorite number.

With each holiday season also comes a special tradition carried on by Karen, in which she buys a Christmas ornament for each of their four children, including Jerry.

"Every year since the day they were born, my wife has bought a Christmas tree ornament for each one of them, and today she still buys a Christmas tree ornament for each one of them," Morgan says. "She'll buy an ornament that she thinks represents Jerry this year."

The Morgan Family Strong star continues: "We all laugh and cry every Christmas, every holiday, every time we're together. My wife is an expert at making sure to incorporate him in every conversation that we have when we're with the rest of the family. My son told us that they were pregnant a while back, and my wife's like, 'Jerry would be a good middle name.'"

For more of PEOPLE's interview with Craig Morgan, including his thoughts on moving on from the music business, pick up the new issue of the magazine on newsstands Friday.

The singer feels his son's spirit everywhere, whether it's on the tour bus, in the spot where Jerry once sat and played video games, or in the oak trees that he and Jerry planted together years ago.

"They're growing, and every year I go out there and I take real good care of those trees, because they're special — because he and I planted those trees," he says. "Some day here, there will be acorns that fall off of those trees that he and I planted. He loved that."

The family has also stayed in close contact with Jerry's friends, including the ones who were out on the water with him the day of the accident. They visit the Greer family and share life updates like college graduation with the grieving parents.

"All of those kids that were on the boat with him, we know them all very well," he says. "Every one of them come to the cemetery regularly, to the chapel. We talk to them regularly, we keep up with every one of them."

Morgan is chronicling his experiences — from the loss of his son to his Army service and undercover work busting child prostitution rings in Southeast Asia — in a new memoir called God, Family, Country out Sept. 27.

For more from Craig Morgan and an exclusive excerpt from his upcoming book, pick up the latest issue of PEOPLE, on newsstands Friday.