Jennifer Hodge-Williamson
As with everything in life, there are pros and cons when it comes to decision-making. Weighing each allows us to reach a conclusion that we are comfortable living with. When it comes to mulching our gardens, here are a few things to consider.
Mulch of any kind - organic: bark, straw, grass clippings, leaves, pine needles, and non-organic: stone, plastic, landscape fabric - will block weeds and retain moisture to varying degrees. The differences between the two are that organic mulches also return valuable nutrients to the soil as they break down to feed plants and allow air and water filtration through the soil to provide a healthy environment for microorganisms crucial to plants’ abilities to utilize those nutrients. It may be argued that stone offers some small mineral component to the soil, but the process of breaking this down is lengthy and miniscule.
If your choice is to mulch, organic materials are best. They reduce weed seed germination. They feed the soil. Weeds that do grow have roots closer to the mulch layer making them easier to access and remove. Before applying mulch, water the area well so that hydration is available directly to the plants and not locked up by the mulch. Watering dry mulch will prevent moisture from reaching the soil. For mulch to be beneficial you must apply 5 to 10 centimetres (2 to 4 inches). It’s not just a pretty face. Mulch can be applied any time throughout the growing season. As organic mulch breaks down, blows away or is gathered by wildlife for nests, it will be something you will apply every 1 to 2 years. It breaks down - that’s what it’s supposed to do. When I use mulch it is natural and uncoloured. I cannot speak to the dyes that are used in others. I do know that all mulches are not created equally. Undyed mulches hide nothing.
In my experience I veer away from non-organic mulches. Stones alone are simply a growing medium for weed seeds. Stones and fabric together may hold some merit in certain circumstances, but any dirt and seeds that blow onto the surface will root. Mulch on fabric absolutely defeats the purpose. Plastic and fabric kill microorganisms in the soil leaving it sterile and when applied near tree roots create stress and unhealthy growing conditions. Landscape fabric may work for a short time but eventually weeds will push up through it or, more likely, root down through it, making removal arduous and sometimes impossible.
I personally leave most of my soil open. This supports ground-dwelling bees and simplifies annual weed control with use of a hoe. My plants grow close together to mulch themselves and very little weeding is required. I use creeping plants which are beautiful mulches on their own. In the fall I leave the leaves and plant debris to compost on the spot while also providing the properties of a mulch. It works for me.
