Hello again, Westside Gardeners! As we enter early winter, many of our woody, herbaceous perennials and shrubs still show signs of summer stress. Foliage is disfigured and burnt. Stems are discolored and weak. How can we help our friends?
Most importantly, we as gardeners must check the mulch around the plant material. Wood mulch applied too thickly and allowed to dry out may create a water-repelling condition that leads to poor performance and even death.
Wood mulches like arbor mulch have many benefits, including reducing weed competition, enhancing soil temperature for optimum root growth, and improving moisture retention.
However, some of our favorite mulches can become detrimental regarding moisture when incorrectly used.
When wood mulches are applied too thickly and allowed to dry out completely, conditions benefit the colonization of certain fungi that create water-repelling conditions throughout the mulch. This condition is coined “hydrophobic” and commonly called “hyper dry.”
Avoiding conditions that exacerbate this situation is the first line of defense. When applying mulch, ensure it is well-moistened and will allow overhead irrigation or rainfall to penetrate.
Wood mulches that receive routine overhead irrigation are less prone to this problem. However, don’t underestimate if it has been applied too thickly.
Because wood mulches are carbon-based, add organic fertilizer and biostimulants to the soil before applying mulch.
The fertilizer should also contain amino acids and essential elements. Applying nutrients first prevents the nutrients from becoming tied up in the mulch and allows them to move into the root zone unimpeded.
Plants synthesize amino acids from the primary elements, carbon, oxygen from the air and hydrogen from water in the soil.
Hydration occurs by means of photosynthesis and combining it with nitrogen, which plants obtain from the soil, leading to the synthesis of collateral metabolic pathways.
Avoid using raw wood products like redwood. These types of products may promote hydrophobic conditions, but compost doesn’t. Anyone out there needing advice can feel free to contact me.
Mark Koehler of Los Banos is an arborist and master gardener who has degrees in landscape architecture and landscape horticulture from UC Berkeley and Northeastern University. Please send any questions or comments to markgardenguru@gmail.com.
