Constructing a dry-stack stone wall is a muscle-building, creative and meditative project that allows you to play with a gardener’s favorite accent – rocks. You will get up-close and personal with them, playing with and exploring their shapes, weights and individualities.
Dry-stack stone walls fold perfectly into any landscape style and retain earth in a more natural way than retaining blocks, and as effectively. Gravity and physics is the mortar and when done thoughtfully, they’ll stand forever. Plus, they look like they’ve been there forever. The process is straightforward – you are basically piling rocks vertically against and into the earth while fitting them together like a jigsaw puzzle, as best you can. It’s quite relaxing and great exercise. You just go stone by stone.
Gather your rocks. I believe this is the most challenging part. Separate them into three piles by size and also, set aside the especially flat ones that will work well for the capstone top. Angular rocks generally work better than round, but round can work with the right positioning. Rocks can be hard to come by, so I am a fan of making use of whatever you have. You’ve got it made if you own or have access to property that contains rocks. Farmers are a good go-to and the free listings on Craigslist sometimes have them. And, of course, you can purchase them at many garden centers. Even a 10-rock wall has impact.
Position your wall. Walls that retain the earth generally follow the curve of the base of a hill or are straight and cut into a hill to make a driveway or walkway, as in my example. You can either build your wall then backfill with soil or excavate into a hill, digging out just enough dirt to position your rocks. I believe a combination of the two works best, unearthing only as much as is necessary, then positioning the rocks into the earth. If you are building into a slope, this will require excavating deeper at the base and less at the top.
Lay your foundation row. A length of rope or electrical cord helps in the placement of the first row of rocks. Lay a three to four-inch deep base of gravel, crushed stone or sand as wide as the planned width of your wall plus at least an inch on each side. Like laying patio block, this well reduce shifting during winter. When piecing the wall together, use a mixture of sizes at all levels, but tend towards the larger ones in your base row.
Build your wall. The fun and sometimes challenging part of building a stone wall is positioning the rocks so they stably nestle into one another. Do your best to choose a rock that looks like it will fit the void you’re attempting to fill, then turn and move it around until it “clicks” into place. If it takes more than five or so attempts…try another rock. Strive to have only minimal spaces between rocks, using very small rocks when necessary to stabilize. See that the vertical and horizontal spaces between the rocks are staggered, like a brick wall.
Whether backfilling or positioning rocks into the wall, make sure that the back of the wall is well supported by the earth. Slightly angle the front of the wall towards the earth, about 1-inch for every two feet. Try for a flat, smooth face to the wall. That said, the goal is to have the rocks settle in snugly, so make that your first priority while attempting to achieve a smooth profile. View your work from all angles as you go to help achieve a good looking, uniform wall.
Capping it off. When you’ve reached your desired height, top the wall off with rocks that are relatively flat and will give a finished look, like a ledge.
This article appeared in my DIY column in Northern Gardener magazine.