The Woodlands homeowners associations try hard to control what can and can’t be done there to keep things “woodsy” and natural. So, how and why have they allowed so much unnatural dyed mulch to dominate new home construction?
“Wood mulches can slow the growth of established plants and just plain starve new ones to death by ‘tying up’ the available food in your soil, a process known as “nitrogen immobilization.” Those are the exact words of one of the nation’s leading experts on mulch – Dr. Harry Hoitink, revered soil scientist and professor emeritus at The Ohio State University. “Wood is carbon, and carbon always looks for nitrogen to bond with so it can break down into new soil,”
Hoitink says. “That’s the principle behind composting. Wood mulches take that nitrogen right out of the soil, out-competing your nitrogen-needy plants. And dyed mulches ARE THE ABSOLUTE WORST offenders. The wood in these old pallets, chipped up and sprayed with dye, is the worst type of mulch for use around new landscapes … especially on smaller shrubbery, annuals, perennials and just smaller plants.”
Double-shredded Texas native hardwood mulches are composed of finely shredded wood mixed with compost, Texas-native varieties that also include ample compost, which is beneficial to the soil, not harmful. Dyed mulches are nothing more than chips and chunks of wood – neither mixed with anything organic nor shredded. Gardeners can see the sick plants almost always brought on by nitrogen immobilization.
Some landscapers do know this. But a homeowner says they want black, and instead of running the risk of losing business, the landscaper simply puts down black mulch. Unscrupulous landscapers who know that black-dyed mulch loses its color quickly count on re-applications throughout the year for a customer who wants a consistent “black look.”