Social Distance XVI – Garden Paths

This column continues explorations of three kinds of gardening activities that can respond to our creative energies, support healthful exercise, and improve the quality and enjoyment of our living environments.

Care for Your Garden

We recently touched on the Big Three of Weeding: pulling, solarizing and mulching. In this column, we survey ways to minimize weed growth on garden paths.

Some gardens consist of lawns with planted garden beds that either around or within the grassy area. In landscapes with large garden beds the lawn might take the form of narrow paths between the planted areas. In either case, managing weed growth in lawns requires supporting vigorous growth of the grass (good for the environment) or applying a broadleaf weed killer (bad for the environment).

The following notes focus on non-grassy garden paths.

The most basic garden path is bare soil, compacted by foot traffic. Such areas still can foster weed growth, although a layer of organic mulch could help to discourage weed rooting.

The next level of limiting weed growth is to cover basic paths with decomposed granite (“DG”), which is coarser than sand, with angular grains that can be tamped down to form a firm surface. Landscape fabric might be placed on the path below the DG installation.

A three-inch deep layer of DG provides an inexpensive path that is not hospitable to weed growth but weeds eventually will establish roots in the DG and their removal become a time-consuming maintenance task. While landscape fabric discourages weed growth from below, the weeds begin with seeds that winds and birds bring to the path’s surface.

As the DG path becomes weedy, practical weed management could be accomplished with occasional spraying of 20% or 30% vinegar. This organic treatment requires careful handling to protect desirable plants and nearby gardeners from this harsh chemical.

Some advisers recommend household vinegar (5%) mixed with table salt plus a small quantity of liquid detergent as a surfactant. Spraying with this solution will trouble weaker weeds but doesn’t really get the job done.

A DG path can be protected from weed growth with the use of a stabilizer that is added to the DG before installation. This method yields an attractive, durable, and permeable surface that is less expensive than concrete. Stabilized DG is best installed over a bed of crushed gravel. For one example of this product, see

The most stable and durable type of DG uses natural resign mixed in with the decomposed granite aggregate. This creates an asphalt-like material, but with a more natural look.

Then, we have a variety of hardscape paths. These include natural flagstones, cut stone slabs, common bricks, and concrete pavers. These materials should be installed over a bed of crushed gravel for stability plus a layer of sand for adjustment to a level surface. The gaps between the paving materials can be filled with sand, but such gaps eventually will harbor weed seeds and result in a weeding task.

A better method for filling gaps between paving materials is the use of polymeric sand, which is available from landscape suppliers. This filler is a mixture of fine sands and polymers that, when mixed with water, form a binding agent that locks the sand particles together and results in a uniform, durable surface.

Concrete provides ultimate and most costly protection from weed growth on garden paths. This approach includes installing concrete under and between the paving materials or creating a solid path by pouring concrete between forms. In either approach, a bed of crushed gravel is needed in for stability.

Advance Your Gardening Knowledge

As always, useful information on each of these methods for weed control on garden paths can be found by searching the Internet for the respective keywords. A search of YouTube also will lead to video clips that demonstrate the methods.

Enrich Your Gardening Days

The UCSC Arboretum has reopened, following a closure period in response to the Covid-19 pandemic. This extraordinary facility offers a pleasant and completely safe opportunity to  enjoy unique garden vistas and gather inspiration for your own gardening ventures.

The Wollemi Pine (Wollemia nobilis) had been known only from fossils up to 200 million years old, but was discovered in Australia in 1994 and is being grown again in botanical gardens.

Erica mammosa ‘Ninepin’. The species name for this South African heath plant refers to the udder-like shape of the flowers.
The Spider Flower (Grevillea)grows in a wide range of sizes

Photographs with this column have been created by Bill Bishoff, the Arboretum’s volunteer photographer, as samples of the many plants that are in bloom at the “Arb” right now.

The Arboretum’s hours are from 9:00 to 5:00 every day. Admission is $5 for adults, $2 for children, and free for volunteers and members. When visiting, practice social distancing, wear a mask and bring your own drinking water.

For driving directions and information about being an Arboretum member or volunteer, visit The website also has links to purchase Arboretum plants online for curbside pick-up.

Keep your emotions positive and your viruses negative and enjoy your garden.

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

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 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.