Don't mess with a good thing!
California Context: Mulch is critical to the health of our soils and plants. Over the winter, the mulch decomposes into compost, which replenishes the soil with nutrients plants need. A well-dressed mulch layer will also minimize weed germination, and what few are able to take hold, weeds are typically easier to pull from moist, well composted soil. As the California rains recede, replenishing beds with mulch helps keep moisture in while continuing to abate weeds throughout the dry season. Installed well, lasting benefits occur, such as less weeding, pesticides and fertilizers, soils become aerobic, beneficial insects and birds return, and plants are healthy; composting mulch tends to hold more moisture, reducing the risk of fire. Choosing the wrong mulch, and most of those benefits are degraded.
Color Me Red: Generally, red attracts the eye for “negative (e.g., blood, fire, danger), and positive (e.g., sex, food) connotations.” While red flowers excite and delight, why would we try to draw attention to the ground with red mulch? The eye will first look at the mulch before anything else in the landscape, so red mulch tops our eligibility requirements.
Hair Not Mulch: Adding any color to mulch should make one wary. While the colorant may not be harmful by its properties alone, there is a more concerning consideration: most dyed mulch is hiding the material makeup of the mulch itself: construction byproducts, leftover pallets, and possibly chemical-laden treated lumber. These questionable materials leach into the soil causing harm in their path. The color also slows the decomposition down, which means the mulch is not composting and contributing to the health of the soil. Keep color for hair, not mulch I say!
Gorilla Be Gone: Shredded redwood or cedar barks are known in the industry as “gorilla mulch.” While it may be useful protecting hillside stability, using it as a mulch in all other garden areas reaps little benefit. Of the wood mulches, it also is highly vulnerable to fire, so, California, let’s not go there!
Bouncing Baby: Rubber mulch has been touted as a great alternative to wood mulches, since it essentially does not decompose and helps lessen impacts when children fall in playgrounds. But I ask any parent, why would you let your children play on a pile of used tires? Not only is the rubber the most combustible of mulch products, tires are known carcinogens linked to cancer. Let’s leave recycled rubber where it belongs, as an additive to roadway asphalt…. until another solution can be found. Besides, what could it possibly contribute to a healthy soil let alone your child?
Rock Doesn’t Roll: There are numerous colors and textures available, and there are examples where rock mulch is an acceptable alternative (think Zen garden, pathway material, or visual accent). To use broadly as a ground cover heats up the soil making it hostile to plant roots and organisms that contribute to a healthy environment.
Glass House: Similar to rock, recycled glass has become all the rage for designers in need of a colorful accent in fanciful gardens. Done right, glass can have an ethereal effect. Mostly, it’s done wrong and fails to contribute to healthy soil, plants, and good design.
Color Concession: There are some dyed mulches that are made strictly from forest products, such as tree waste from pruning. While the color itself is questionable, the wood type is an appropriate material. Further concession for natural colors, such as brown, so that the ground recedes and not shouting in red, “Look at me!”
A Life of Compost: Mulch derived from garden trimmings, including lawns not subject to the myriad of available chemicals, will start composting the minute it is piled up and its temperature rises. Gardeners are doing it right when they seek out materials made only from forest and garden products and look forward to its benefits to the soil and environment.
Power Gardener: One who composts their own material rather than shipping it off to a processing plant some miles away. To succeed means creating a compost pile, managing it, and spreading throughout the garden as available. Kitchen veggie scraps are a bonus.