When you look at your garden beds and borders, do you see any bare soil? If so, mulch is in order.Mulch is defined as a protective layer applied over soil to retain moisture, suppress weeds and moderate soil temperature around plants, as well as in uncultivated areas. But if used incorrectly, mulch can cause more harm than good.The right kind of mulchFolks use everything from gravel, plastic sheeting and shredded tires to organic materials like compost, pine needles, shredded bark, hay, straw and wood chips. Some are better than others, to say the least.Gravel and stones reduce weeds and retain some moisture, but affect plants differently than organic mulch. Stone absorbs heat, which can scorch plants and roots. Removing gravel later can be a Sisyphean task.Still, in fire zones, gravel is recommended to cover soil, since organic mulches are flammable.
Shredded tires? Please don’t. Crumb rubber can contain volatile organic compounds, lead and other heavy metals. And even if you remove it someday, the chemicals it leaves behind will remain in the soil for a very long time — maybe permanently — unless you’re willing to strip out and replace layers of soil. It’s hard to imagine that tradeoff being worth it.
