This Month’s Water-Wise Focus: Mulch
Ego-Driven Gardening
By Rosamond C. Rodman
No, this isn’t about having a greener lawn, heftier squash or showier flowers. Psycho-analyst Sigmund Freud argued that the ego functioned as the arbitrating middle layer of the psyche, between the id (instinctive, often unconscious urges and impulses, such as libido) and the super-ego (the results-focused, critical and moralizing function of the mind).
By extension, think of the id as your soil and your plants and harvest as the super-ego. Mulch, then, functions as a gardener’s ego. Unfortunately, people think of the ego as a negative personality trait when in fact, the ego is a necessary psychic component, providing a filter between the self and the outer world. The Freudian ego is like the gardener’s mulch — a protective layer that ensures appropriate relationship between a healthy, libidinous soil and the external products of the garden – gorgeous flowers, nutritious vegetables, and aromatic herbs.
Mulch
Mulch is a protective layer of material that is spread on top of the soil. “Maintain a thick mulch of organic matter covering garden soil throughout the summer. This prevents crusting and cracking of the soil surface, holds in moisture, encourages earthworms, moderates soil temperatures for optimum root growth, improves the soil as it decomposes, deters weeds from germinating, and enables easy picking of weeds that do get a start. A 2 to 4 inch layer of mulch decreases evaporation from the soil by 70 percent or more, allowing you to water less often (but still deeply),” says Yvonne Savio, the University of California Extension Common Ground Program manager and 2010 Horticulturalist of the Year.
There are two types of mulches. Organic mulches, such as straw, bark, grass clippings; and inorganic mulches, such as stones, newspaper, and plastic. They each have their purposes and benefits. Organic mulches (such as hay, bark, leaves) break down over time and amend the soil. Inorganic mulches (newspaper, black plastic, stones) moderate temperatures, heating up the soil in cool coastal climes, and decreasing soil temperatures in inland valleys.
Mulch and Compost
Mulch is sometimes confused with compost, but they are not the same. Compost is organic plant matter that is decayed enough to directly enrich the soil without requiring extra nitrogen from the soil to break down further. It functions to directly amend the soil. Mulch, on the other hand, can eventually break down and affect the soil composition, but only over time. Its purpose is different from compost.
Mulch and Water Conservation
There are several reasons to mulch, all of them tied directly to water conservation.
- To retain moisture around a plant and slow soil evaporation.
- To reduce weeds (that in addition to being unwanted also steal water from the plants to which you want to give water).
- To raise or lower the soil temperature, the latter of which is often very important in time of high temperatures.
- To prevent soil compaction after heavy rains and erosion from wind.
Sources
Keep in mind why you are mulching in the first place – do you wish to heat up soil? If so, black plastic works well. Is your effort to control weeds and maintain moisture? In this case, consider tree leaves, wood bark or chips, or straw.
- Go: You can always purchase mulch at a local hardware or garden supply store. Frequently, though, you can find sources of mulch for free or minimal cost to you.
- Online: Use the CalRecycle page to locate sources of (often free) mulch and compost near you http://www.calrecycle.ca.gov/Organics/SupplierList/default.asp by linking you to local allied industries (tree trimming companies).
- Call: Contact Altadena’s own “Sodfather” a.k.a. “the Guru of Doo-Doo” a.k.a. Tim Dundon at 626-794-1351. Call him to arrange pick up in your own truck (free), or delivery by him (minimal fee).
Application of Mulch
First, clear the area of weeds before applying mulch. Once you have done so, spread a layer of mulch of approximately two to four (2-4) inches. NB: clear a space of an inch or two immediately at the base or collar of the main plant stem to prevent excessive humidity and disease or pests.
The best time to apply mulch is in the late spring to June, after soil temperatures have risen sufficiently but before it gets really hot. This ensures maximum retention of moisture but not excessive moisture and plant rot. Refresh your mulch again in the late fall, before temperatures drop substantially, as a way to maintain and protect warmth in your soils, and to prevent soil erosion due to winter winds and rain.
Become an Ego-Driven Gardener: Mulch!
Mulching is probably the simplest and most effective way to conserve water in your garden. Some clever person described mulch as “sunblock for your plants” but a better analogy likens mulch to the Freudian ego. Mulch gives your garden a protective layer that simultaneously benefits the soil, enriches the plants growing from the soil, and conserves water.
Next month: Effective Watering
