People in their 50s, 60s and beyond look at starting gardens differently from those in their 40s and younger.

Assuming they stay put, people in their 40s can expect three decades or more to enjoy the trees, shrubs and perennials they plant this growing season. Once they get past 50 and are creating new garden beds, they realize that, while they will enjoy the development of the garden, it will not reach its full, mature beauty until they have died.

Older people start gardens for various reasons. Some have downsized into a smaller home, moved to a new home to be nearer to children and grandchildren, or recently retired and moved to Maine. Others, because they have the time and experience, are planting or helping to plant gardens for offspring, friends and neighbors.

People planting new gardens will want to make sure the plants will last for many generations, growing in beauty over time and requiring minimal maintenance. At least that is what Jane Beckwith, corresponding secretary for the Cape Elizabeth Historical Society, proposed recently when my wife Nancy and I dropped off information about one of Nancy’s relatives.

Beckwith called it a “heritage garden,” and she wanted me to write a column about how to grow one. The title heritage garden makes sense for her idea, but the term has already been given to gardens that match the style of older homes. Maybe we’ll call it a forever garden, one that straddles generations.

The garden will be a mix of natives plants, because natives will become ever more important to the environment in the future, and well-behaved non-natives, as a tie to the types of gardens that our ancestors grew.

These gardens will not include trees, despite the Greek proverb that says, “A society grows great when old men plant trees whose shade they know they shall never sit in.” Do plant long-lived, native trees like maples, oaks and hickories elsewhere on your property, but they would overwhelm the kind of garden envisioned here.

The shrubs could include azaleas, rhododendrons, viburnums, magnolia, mountain laurel and lilacs. But not any of these species would do. For this garden they would have to be tried-and-true plants that will live for generations and have already been in the market for a generation or two.

The rhododendrons, for example, would be the old-style large-leaved rhododendrons like Rosebay rather than the small-leaved relatives of the PJM rhododendron. Similarly, the Miss Kim lilac is too modern, so the lilacs would have to be the purple and white common varieties or their hybrids.

Magnolias would be stellata, or star magnolias. Until recently, the saucer magnolia wouldn’t survive the Maine winter, but warmer winters, as well as the introduction of hardier varieties, and have made it possible to grow them here. I would pick the “Lyle’s Legacy,” because it was developed at my alma mater, the University of Maine, and if it can survive the winters there it will do fine in southern Maine.

The hydrangeas would be Arborescens, probably “Annabelle” because it has thrived 40 years with minimal attention in our garden, and PeeGee, or paniculata grandiflora, which is Zone 3 and a garden staple, seen often in older cemeteries. How much attention do they get there?

This garden needs a needled evergreen, and I rejected many. Most small pines don’t last long. Arborvitae and yews get eaten by deer, and I don’t like the look of them because too many homes had them smacked up against the foundation when I was growing up. Chamaecyparis is OK, but it hasn’t been around long enough.

I decided to go with birds nest spruce because it is attractive and low maintenance. Catalogs will tell you it has an ultimate height of three feet, but ours has grown to five feet in 30 years. It can be pruned to keep it shorter without hurting the looks.

For early blossoms, plant a lot of daffodils. They last forever, partly because they are poisonous and no animals eat them, and are gorgeous in whites and yellows.

For perennials, start with peonies. They have large, showy blossoms, are traditional and last forever. Their foliage looks good after the flowers are spent and, in time, they can be divided and shared with friends.

Irises are a must. Bearded and Siberian irises bloom at different times, so the bloom time will be extended and they take very little care.

A couple of decades ago, I would have recommended lilies. Since the arrival of the lily leaf beetle, a low-maintenance forever garden would have to forgo this beauty. Instead, plant a lot of daylilies – the traditional ones, not the repeat bloomers like Stella d’Oro. The blossoms can be huge and cover the rainbow.

Black-eyed susans, or rudbeckia, and phlox will provide color in the middle of the summer, and if you are willing to ignore downy mildew on the phlox, they are low maintenance.

This isn’t a hard-and-fast list. Alter it to fit your taste. Just remember the key ingredients: Traditional, low-maintenance, long-lasting and beautiful.

Your great-grandchildren – or whoever owns your garden in 50 years – will thank you.

TOM ATWELL is a freelance writer gardening in Cape Elizabeth. He can be contacted at at: tomatwell@me.com.