Revere mulch

You view mulch as optional or boring? To quote Julia Roberts in Pretty Woman, “Big mistake. Big. Huge.”

No matter the climate zone or garden type, mulch is universally recommended. The stated context is as a ‘protective layer’ over soil and covered by plants. That is vital in dry climates, and so is its unheralded capacity as a visible design element.

Cut bark or gorilla hair fills our California beds, and gravel or bark defines our paths. These meek materials’ utilitarian capabilities combined with inventive supplanting of lawn and groundcover create a hefty conservation snowball effect. Relative ranking of the water-wise merits, derived from scientific studies and on-site observations, is:

Retains 35-70% more moisture than bare soil
Improves water efficiency up to 25% by inhibiting competition from weeds
Offers no-water design alternatives to carpets of greedy grass
Limits erosion, especially on slopes, as well as soil compaction so plants get more water
Increases overall plant performance by up to 67% as measured in height, diameter, and leaf size
Moderates temperature as much as 10° so roots are cooler when it’s hot and warmer when it’s cool
Conditions soil by providing nutrition and encouraging beneficial organisms and worms

Hailed as “icing on the cake,” “gardener’s best friend,” “unsung hero,” “secret weapon,” and even “birth control for weeds,” this unexciting substance, especially in organic form, has proven a top sustainable gardening principle. Check out these exemplars on varieties and application:

“Mulching,” USDA Natural Resources Conservation Services, Arizona
“Mulches for the Landscape,” by Robert J. Black, Edward F. Gilman, Gary W. Knox and Kathleen C. Ruppert of University of Florida, Institute of Food and Agricultural Sciences
“Understanding Mulches,” Mother Nature’s Backyard by Board of the Friends of Gardena Willows Wetland Preserve
“Impact of Mulches on Landscape Plants and the Environment—A Review,” by Linda Chalker-Scott of Washington State University, Puyallup Research and Extension Center
“Mulch–a Gardener’s Best Friend,” by Lyn Gannon of University of California, Master Gardener Program of Sonoma County
“A Quick Primer on Mulches,” MGABC Master Gardeners Association of BC