Mulching represents a gardener’s not-so-secret strategy for achieving the universal objective: a low-maintenance garden.
If your garden is time-consuming, frustrating and disappointing, it probably needs mulching.
Several other possible causes should be considered: nutrient-poor soil, lack of irrigation, inappropriate plant selection, etc., but let’s focus for the moment on mulching.
A three-inch deep layer of an organic mulch between plants discourages weed growth, conserves water and, in time, breaks down to add nutrients and texture to garden soil.
We should not ignore the downsides of mulching. For example, a larger garden will require several cubic yards of organic mulch, leading to significant charges from a landscape supply company for the material and its delivery. In addition, distributing the mulch within the garden, while not difficult, consumes time and energy.
One more downside: organic mulches decompose in time, so the time and expense will have to be incurred again. Finer mulch materials break down faster than coarse materials.
Some organic mulch is free, e.g., disease-free wood chips that tree services will dump on your property, upon request (to avoid landfill charges), or seaweed harvested during low tide. Wood chips might be regarded as less attractive than finer mulches, and seaweed, although excellent in nutrient content, often is troublesome to gather, buddy and smelly.
A landscape supply company will offer a variety of organic mulches in bulk, e.g., redwood sawdust, shredded cedar, fir bark and gorilla hair (shredded redwood bark, really), in a range of sizes and prices.
Another option is cocoa shell mulch, which is available in bags of two cubic feet for about $5.00. This material looks good, emits a nice fragrance and breaks down slowly, but contains theobromine, a natural compound that if eaten is highly toxic to dogs and cats.
The gardener could consider each of the available options, and perhaps try a sample bag in the garden.
Home supply stores offer organic mulches in bags of two cubic feet of material. These can be appropriate for smaller beds, but for larger projects will be more expensive than bulk materials. To move one or two yards of mulch, it’s good to have a friend with a pickup truck.
Gravel mulch might be preferred for a rock garden or succulent garden. For a rock garden in particular, gravel mulch simulates scree, the debris of broken rock seen on mountain slopes.
Like organic mulches, gravel mulch discourages weeds, conserves moisture and looks better than bare soil. Gravel is much more expensive per cubic yard than organic mulches, but a one-inch layer should be enough and gravel doesn’t decompose. Gravel mulch is difficult to remove, so for practical purposes treat the installation as permanent.
Enjoy your mulched garden.
Estimating Mulch Needs
To decide how much material you will need, estimate the surface area of the garden bed(s) to be mulched: length times width (in feet). Multiple by the intended depth of the mulch layer: for a three-inch layer, multiply by .25. Finally, convert cubic feet to cubic yards by dividing by 27.
Example: a 12 feet x 18 feet garden bed has a surface area of 216 square feet. For a three-inch layer of mulch, .25 x 216 yields 54 cubic feet. Divide by 27 to determine a need for two yards of mulch.
An interesting article, How to Use Seaweed to Mulch Your Garden, is available on the website for Eartheasy: Solutions for Sustainable Living. Gardeners who live close to the beach might wish to try this mulch material, but it seems too smelly and buggy for my taste. It also decomposes into slime rather quickly.