Planning a Garden Staircase

The many pleasures of gardening include having multiple projects going at any given time. The projects typically are at different stages of development, ranging from vague interest to almost done.

The projects also differ in duration and immediacy. Some are time-sensitive, e.g., removing weed before they set seed, or installing plants before the onset of winter rains, or pruning apple trees before bud break.

Other projects can be pursued at any time, whenever the mood strikes and enough planning has been accomplished.

One such project now waiting for my attention is the replacement of a short flight of wooden steps that have begun to deteriorate. These were created some time back by the simple process of installing railroad ties on a slope. The wooden pieces we call “railroad ties” are not actual ties, which I believe are soaked in creosote and not really good for gardens. They are instead 6” x 6” lumber that is 36” or 48” long.

The slope at issue is neither long nor steep. I pulled a cord from the top of the slope, used string level to adjust the height of the cord above the bottom of the slope, and measured the drop at twenty-four inches. By the way, I used a non-stretchy cord (Mason’s twine) to minimize sagging along the length of the run.

Once the height of the stairway has been determined, the next decision concerns the rise of the steps and the depth of the treads. These measurements should relate to each other and should be consistent throughout the stairway (even a short one).

Garden steps might use basic dimensions: a rise of 5 1/2 to 7 inches and a tread of 12 to 18 inches. Or they might have a shorter rise and a longer tread to provide a slower walk up the slope. For a stairway that would be a comfortable walk for most people, the tread plus twice the height of the riser should equal 26 or 27 inches: Tread + (2 × Riser) = 26 or 27.

For a chart of several suitable combinations of tread and riser, visit www.gardengatemagazine.com/64stepchart/

My stairway project needs to elevate walkers just two feet over a distance of roughly ten feet, so I could use 4” risers with 18” treads. This would require six steps and risers, extending over a nine feet horizontal distance. I would level the lower part of the path beyond the nine-foot distance.

There would be a slight curve to this stairway, so I will keep the centerline of the treads to a consistent 18 inches.

The next phase of this project is to select the material for the steps. There are countless options, including cut stone, natural stone, cast concrete, salvaged concrete (“urbanite”), wood, and perhaps others. For design ideas and exemplary uses of various materials, visit www.pinterest.com and search for “garden steps.”

California Redwood (Sequoia sempervirens) lasts well when planted in soil, and is a good choice for garden steps. (Other rot-resistant woods include black locust (Robinia pseudoacacia), teak (Tectona grandis), ipe (Tabebuia spp), and bald cypress (Taxodium distichum), but these are more expensive materials for steps.)

Stone steps would be nice but might require more cost and more labor.