The use of wood chips as mulch in gardens has sometimes been disputed for its benefits, yet research can refute negative claims and prove the benefit to soil and plants.
According to a Master Gardener article, "Wood chips are considered to be slow decomposers, as their tissues are rich in lignin, suberin, tannins, and other decomposition-resistant, natural compounds. Thus, wood chips supply nutrients slowly to the system; at the same time they absorb significant amounts of water that is slowly released to the soil. It is not surprising that wood chips have been cited as superior mulches."
Let's look at some of the claims and the counter claims for the use of wood chip mulch.
Claim: Woody mulches will acidify soils.
Response: There is no evidence of this. Slome changes in pH may be found in the decomposing mulch layer itself, but these have little effect on underlying soils.
Claim: Woody mulches leach allelopathic chemicals that kill other plants.
Response: Some plant materials contain allelopathic chemicals (these can prevent seeds from germinating or kill young seedlings), but only a few wood materials have this substance: black walnut is one.
Claim: Wood chips could be a fire hazard, particularly when they are used on landscapes around structures.
Response: Wood chips are the least flammable of the organic mulches.
Claim: Wood chip mulch ties up nitrogen and causes deficiencies in plants.
Response: Actually, many studies have demonstrated that wood mulch materials increase nutrient levels in soils and/or associated plant foliage.
Concern: Woody mulches will attract termites, carpenter ants, and other pests.
Response: Many wood-based mulches are actually insect repellent.
Overall, it appears that many of the negative claims have no scientific evidence. Organic material is a great option for keeping down weeds and improving plant health. It's also appealing to the eye, and makes maintenance easier for the gardener.
Hay Creek Companies manufactures wood mulch from reclaimed wood. It is free of chemicals, and our colored mulch is made with an environmentally safe colorant that won’t harm your soil or other plants. As a landscape mulch manufacturer, we deliver bulk wood mulch and bagged mulch to our distributors around Wisconsin, who make our product available for their retail customers. It is available by the truckload for landscaping companies and garden centers that would like to become distributors. Contact us if you'd like to know more about providing wood chip landscape mulch to your customers.