This Father’s Day, Thomas Rose can reflect on how he raised not only his own children decades ago, but also the dozens of foster children he and his wife have welcomed during the couple’s senior years.

Rose and his wife, Ann Rose, have been foster parents to 71 children over the past 15 years, and they’re hoping to welcome a 72nd soon to their Allentown, Pennsylvania, home.

“It’s very satisfying,” Rose told CNN’s Fredricka Whitfield of his foster parenting experience on Saturday. “It’s really a lot of fun to see little kids develop and go from not being able to sit up to maybe being able to crawl and then walk and then talk. So it’s pretty rewarding.”

The Roses became first-time foster parents in August 1996, well after they had their own kids. Thomas is in his 70s, and Ann is in her 80s, CNN affiliate WFMZ reported.

“We have grandchildren. They were getting older (and) didn’t have any babies, so we thought we’d do this,” Ann Rose told WFMZ.

Though they’ve taken in dozens of children, the Roses usually aren’t outnumbered at home. Children don’t necessarily stay with foster parents for long, and the Roses rarely have had more than two foster children at a time.

They try to provide children with a loving environment and “teach them to have fun and get a sense of humor and, if they’re old enough … some manners,” Thomas Rose said.

“Some we’ve had for a very short time, and you lose track of them. But some of the kids we had for quite a while (that) you stay in contact with – maybe about 10% of them,” he told Whitfield. “One little girl we got when she was 2 days old. We had her for two years, and she’s going to be 10 years old now, and she comes to visit us for weeks at a time in the summer and around Christmastime.

“So it’s kind of neat when they come back.”

Thomas Rose said he’d tell new fathers that children grow up fast, so fathers need to “love them to bits and have fun with them.”

For any father, new or experienced, he’d advise patience.

“They’re raising something very special. They can just be there for their kids and love them and cherish them, really,” he said. “And it’s not just the dads. Moms and dads have to work together so much. … Just be there to support your kids. Don’t be impatient with them.”

He told WFMZ that the hardest part of foster parenting is knowing that the arrangement is temporary.

“Part of your responsibility is to take care of them while you have them. The giving-them-up part, while it is hard, is something you have to do,” he said.