Mothers and daughters talk about all kinds of things. But there is one conversation Susan Beauregard, 49, of Hampton, Conn., is reluctant to have with her 89-year-old mother, Anita Shear: What to do — eventually — with Mrs. Shear’s beloved set of Lenox china?

Ms. Beauregard said she never uses her own fine china, which she received as a wedding gift long ago. “I feel obligated to take my mom’s Lenox, but it’s just going to sit in the cupboard next to my stuff,” she said.

The only heirlooms she wants from her mother, who lives about an hour away, in the home where Ms. Beauregard was raised, are a few pictures and her mother’s wedding band and engagement ring, which she plans to pass along to her son.

So, in a quandary familiar to many adults who must soon dispose of the beloved stuff their parents would love them to inherit, Ms. Beauregard has to break it to her mother that she does not intend to keep the Hitchcock dining room set or the buffet full of matching Lenox dinnerware, saucers and gravy boats.

As baby boomers grow older, the volume of unwanted keepsakes and family heirlooms is poised to grow — along with the number of delicate conversations about what to do with them. According to a 2014 United States census report, more than 20 percent of America’s population will be 65 or older by 2030. As these waves of older adults start moving to smaller dwellings, assisted living facilities or retirementhomes, they and their kin will have to part with household possessions that the heirs simply don’t want.

“We went from a 3,000-square-foot colonial with three floors to a single-story, 1,400-square-foot living space,” said Tena Bluhm, 76, formerly of Fairfax, Va. She and her 77-year-old husband, Ray Bluhm, moved this month to a retirement community in Lake Ridge, Va.

Before the move, their two adult children took a handful of items, including a new bed and a dining table and chairs. But Mrs. Bluhm could not interest them in “the china and the silver and the crystal,” her own generation’s hallmarks of a properly furnished, middle-class home.

The competitive accumulation of material goods, a cornerstone of the American dream, dates to the post-World War II economy, when returning veterans fled the cities to establish homes and status in the suburbs. Couples married when they were young, and wedding gifts were meant to be used — and treasured — for life.

“Americans spent to keep up with the Joneses, using their possessions to make the statement that they were not failing in their careers,” wrote Juliet B. Schor, the Boston College sociologist, in her 1998 book, “The Overspent American: Why We Want What We Don’t Need.”

But for a variety of social, cultural, and economic reasons, this is no longer the case. Today’s young adults tend to acquire household goods that they consider temporary or disposable, from online retailers or stores like Ikea and Target, instead of inheriting them from parents or grandparents.

This represents a significant shift in material culture, said Mary Kay Buysse, executive director of the National Association of Senior Move Managers, a professional organization of moving specialists who help older people downsize.

“This is the first time we’re seeing a kink in the chain of passing down mementos from one generation to another,” Ms. Buysse said in a telephone interview from the group’s headquarters in Hinsdale, Ill.

Accordingly, the senior move management industry has experienced unprecedented growth in recent years, Ms. Buysse said. These move managers usually charge an hourly rate, typically $50 to $125. They spend time with clients, helping them sort through years of accumulated possessions and make decisions about what to dispose, what to donate to charities and what to try to fit into their new living spaces.

Final costs of the service, which may also involve an estate sale, can be $2,500 to $5,000 or more, depending on the size of the home and the density of its contents.

“We found that seniors have more needs than just the sale of their estates,” said Tracy Niro, a managing partner of Wise Moves, a move management company in Gaithersburg, Md.

Once the children have picked over what they want, and the items slated for the next home have been boxed up, the question is, what becomes of the rest?

“Some goes to auction, some goes to eBay, and some goes to our retail shop,” said Chris Fultz, an owner of Nova Liquidations, an estate liquidation company in Luray, Va., that works closely with companies like Wise Moves.

Ms. Niro said her company also works with nonprofits, like Habitat for Humanity, to find new homes for discarded items. Yet even these operations are feeling overwhelmed by the growing inventory of household goods delivered at their doorsteps.

“We are definitely getting overrun with furniture, and about 20 percent more donations of everything than in previous years,” said Michael Frohm, chief operating officer of Goodwill of Greater Washington, in a telephone interview.

Changing aesthetic tastes are also responsible for the overflow.

“The whole ’90s were the English country look, collections, chintz,” said Jennifer Lacker, an antiques appraiser in Mystic, Conn., who cited the influence of the interior designer Mario Buatta (known as the “Prince of Chintz”). The look, she added, was decidedly “rich and lavish.”

Beginning in the 2000s, though, clutter was out, and minimalism in. Mr. Buatta’s paradigm has been replaced most recently by that of Marie Kondo, whose 2014 book, “The Life-Changing Magic of Tidying Up: The Japanese Art of Decluttering and Organizing,” remains a steady best seller.

Millennials are also less inclined to want their parents’ household goods simply because they have no place to put them.

As his parents begin to contemplate moving from their two-story colonial home in Annandale, N.J., to a smaller living space, Travis Miscia, a 30-year-old lawyer, would like to lay claim to a good number of his family’s belongings. But he and his wife live in a two-bedroom apartment in Jersey City that is too small to hold them.

“I am very interested in family history, and I would like a lot of my parents’ things on some level,” Mr. Miscia said, “but I have had to limit myself to taking what I would call primary-source documents, like books and some pictures.”

Another option for older people and their heirs is self-storage. Like the industry that manages moves for older adults, the $32.7 billion storage business is experiencing rapid growth, projected at 3.5 percent annually over the next five years, according to statistics reported this month by SpareFoot Storage Beat, an industry tracker.

Yet often this strategy only postpones the inevitable.

“Some children take the objects just to keep Mom and Dad quiet,” said Roger Schrenk, Mr. Fultz’s business partner at Nova Liquidations. “They’ll take them and store them until Mom’s dead, and then they can’t wait to get rid of them.”

With this in mind, Mrs. Bluhm, whose adult children only wanted the new bed and dining set, recommends a philosophical approach to the process of letting go of possessions that children may not cherish but others may.

“By donating them to charity, I knew they weren’t going to go into a Dumpster and that someone who really wanted them would purchase them,” she said. Though the items are no longer hers, she said, many of her familiar household objects are not altogether gone.

“What I had left were the memories attached to them, in my heart and in my head,” Mrs. Bluhm said.