How to landscape your garden with boulders

Do you know where landscape building blocks come from? I have to admit, before I wrote this article, I had never given it much thought. Corresponding when Sunset‘s editor-in-chief, Hugh Garvey, needed boulders for his front yard in Los Angeles, he also didn’t know exactly where to buy them.

That’s when landscape designer David Godshall of Terremoto took him to Sunburst Decorative Rock in Irwindale, California—and what he found there was a revelation. “It looks like a massive quarry – like a place in the movie Heat,” says Garvey. “An amazing, unexpected, urban landscape that you wouldn’t know is there.”

Then began an education of what it would be like to select, as Garvey calls them, “organic LEGOs” from a rock yard.

What makes boulders so special? “For me, a boulder is an exclamation point [in the garden],” says Molly Sedlacek of OR.CA Landscape Design. “It should be used sparingly, with caution, intent and vibrato.”

Thomas J. History

Ivette Soler, of Ivette Soler Gardens, agrees. “I think there’s something really special about boulders, especially in the western states,” she says. “They are such a part of a narrative here; they mean solid, they mean older, they give a landscape weight and heaviness.”

Boulders have a number of uses. In Garvey’s front yard, the team improvised a path and used them as “little heat reservoirs” for plants, while also holding water in the soil and providing shade for new plantings on the sloping side. Smaller ones can be placed in a dry stack wall (as in, a wall without mortar), used as a threshold or as a stepping stone. Larger stones can take on the role of natural sculpture. A plank can be placed between two boulders to make a seat, or, as Sedlacek has done, a large boulder can be used as a chaise longue.

Here are some basics to brush up on if you’re planning to get boulders for your garden.

Have a plan

In geology, a rock larger than 10 inches in diameter is considered a boulder, while some designers consider 12 inches and up to be the standard. Regardless, weight is a huge factor when it comes to bouldering. Going to a stone yard isn’t like going to Target, where after all you can load everything in your cart and throw a few bags in your car.

“Understanding how heavy a boulder can be is an important part of the training process,” says Sedlacek. In fact, she was once injured by one. “We were pulling a boulder off my van on a ramp and it was probably 500 lbs. The ramp slid out, the boulder fell and it stuck me by my leg. It took five people to roll it off me . It was very scary. Because of that, I love and respect rock even more – and we didn’t learn how to jerry-rig a ramp.”

That said, Soler says you can “be screwed” if you don’t want to work with a landscape designer. “There are really beautiful medium-sized boulders about 2 feet high and 3 feet wide, and a rock yard will have a list of guys willing to move it,” she says. “So buying boulders is not out of reach for the average homeowner. You have to be resourceful, but it can be done.”

Color matters

Do you want to create a natural look or highlight architectural features of your home? “If you are creating natural surroundings, you want to match the color of the stone to the surroundings. That’s how you make a connection between nature and the site you’re on,” says Troy Bankord, of Troy Bankord Design in Palm Springs, California.

Boulder Landscaping - Outdoor seating with fire pit

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On the other hand, for a house in Palm Springs, Bankord used white boulders to pick up the color of a roofline. “It’s really about the mood you’re trying to create,” he says.

Don’t Go Small

Several designers I spoke with said that people tend to select boulders that are too small for their space. “People often think they need something smaller when it’s out of context,” says Bankord.

Sedlacek adds, “For someone using boulders, I always say go up a size. People tend to see it in the quarry and think it’s big enough, but then you get to the job site and you wish, that it was bigger.”

Go underground

You want to bury your boulder by at least a few inches up to a third for a natural look. “A lot of mistakes that homeowners or contractors make is they want to put a boulder on top of the dirt and just have it float, but in nature the soil has washed around it,” Bankord says, suggesting people look at pictures of Joshua Tree to see how deep to bury a boulder.

Suns prefer flat boulders because they are safer. “If you want one that goes up, you might need a base of concrete, and then you use gravel and planting to hide it,” she says. “Safety is the most important thing, so I try not to do that.” Instead, she tries to keep her boulders as stable as possible.

Overall, boulders can make a big personal statement in a yard. “To put something as eternal as a big stone in your project is to say something like, ‘I’m here to stay'” Soler says.

They can also just make you cool. When Garvey’s boulders were delivered, he found his profile in the neighborhood rising. “People said, ‘if you have any extra stones, we’ll take them,'” he says. “Everyone wants to be your friend when you have a big pile of boulders.”


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