Stone is an important part of the garden, a constant that changes only with the light and, over time, with the attachment of moss and lichens. Stone anchors the garden in space, mood, style and, in many ways, time.

As with most products, the most common and sustainable stone is local. Colonial farmers tilled fields and lined the borders – either of their property or a specific field – with the largest of the stones they found. But some people, to show off their wealth or sophistication, used stone from a great distance – even in prehistoric sites such as Newgrange in Ireland and Stonehenge in England.

Stone often has real work to do. When my parents built their home on a steep hill in Farmington, they hired a local contractor to build retaining walls of local stone in the rear and front, so they had enough flat space for a front walkway and a fieldstone patio out back.

The house my wife Nancy and I had built for us in Cape Elizabeth had existing stone walls, to mark the edge of the strawberry field that was there 10 years earlier. We have added to those walls since, using stone we discovered while tilling our garden or planting trees. Big stones make the planting job tougher, but I always enjoy the idea that we are adding major new piece to our walls.

Gordon Hayward, who lives in Vermont, was reared in Connecticut and also owns a home in England, has written several books on stone and spoke at the New England Grows trade show in December.

“I recommend a respectful, thoughtful use of stone in your gardens. You should use stone in an honest, unselfconscious way,” Hayward said. “Stone has come down to us through millions of years. Using stone has deep, deep references in time.”

The classic way to use stone requires talent combined with years of training: the traditional dry-laid stone wall. These walls require a deep, well-drained foundation made by digging out soil and filling that area with gravel and small stones. Built wider at the bottom than at the top with no long, vertical lines between the stones, these walls – created without mortar – are beautiful and last for centuries.

While a dry-laid stone wall would enhance any house, not everyone can afford it. Many other uses of stone are more affordable.

Hayward believes in creating a relationship between a property’s stone and the house or other buildings. A way to build symmetry between a wall and house, he believes, is to measure the height of the chimney: If you place the front wall the same distance from the front of the house as the chimney is tall, it creates harmony on the property.

Although curved walls are trendy, Hayward prefers the straight walls favored by old builders, running parallel and perpendicular to the lines of the house.

Surface stone is easier to add to a garden for a do-it-yourselfer. A stone walkway or patio won’t fall down, and if it does buckle from the frost all it takes to repair it is time and effort.

The stone for walkways and patios depend on your taste. In the Portland area, you can follow the traditions of the city and install cobblestones. Flat flagstones with pea stone in between the flags are attractive and fairly easy to install. Hayward likes pea-stone walkways because he enjoys the sound of the stone crunching beneath his feet. May I just add that pea-stone makes a mess when you use it for a driveway that has to be plowed or snow blown.

He also thinks you should have large areas of stone around the doors to your house, partly so guests have a place to put their luggage while you greet them or say your farewells.

Natural boulders can add to the beauty of the property, but you have to be careful with them. First, if you purchased a boulder because of its lichens or other patina, make sure the delivery company uses rubber padding or other methods to ensure the stone doesn’t get scratched during the move.

I’ve often seen stones just dumped in the center of a lawn. True, the stone breaks up the expanse of green, but if it doesn’t fit in with other parts of the landscape, it looks like, well, you bought some stones and had someone dump them on your lawn. You need to work with the stones to fit them into your landscape.

Hayward likes using large boulders at the ends of stone walls, to give them definition. Two large stones at the end of a path also can serve as a gateway to another section of the garden, with the stone serving as a directional signal. In order for the stone to look natural, he said, bury at least a third of it underground.

Nancy and I have used locally fired brick for our walkways and patios, but we used reclaimed granite for the steps. A local gravel pit used to sell broken granite that had been used as sidewalk edging, window mantels or basement walls for almost nothing, and we took advantage of that. Since that part of the business disappeared, you would probably have to go to a stone store or salvage yard to find granite for such uses.

Other ways to use stone are as benches or even as art forms. If you’ve been to the Coastal Maine Botanical Gardens, you’ve seen some excellent work with stone.

You can buy cast stone ornaments that sometimes look good, but since many of the ornaments are made by pouring concrete into molds, the ornaments may have seams or defects. Hayward advises you to examine these ornaments carefully before you buy them.

Stone’s most important role in the garden is often as a focal point. If you have only plants, you see a sea of green. A good piece of stone – whether a sculpture, a bench, a boulder or a gate post – will draw your eye to a spot in distance and can make your whole landscape come together.

And you can be sure the stone won’t outgrow its space and have to be pruned.

Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at tomatwell@me.com.