Made of coir, coconut fiber, hemp… These new biodegradable mulching fabrics are, for the most part, allowed in organic farming. But the question is, can we use them in our garden or vegetable patch?
Why use biodegradable mulching mats?
- Slowing weed proliferation. With no light, photosynthesis grinds to a halt. Weeds are left in the dark, meaning less weeding sessions for you.
- Slashing your watering since these biodegradable mulching fabrics hold on to soil moisture very well.
- Reducing soil erosion. No more need to fear soil-scouring rain or wind.
- Thwarting formation of a hard crust on your protected soil – no more runs of the hoe.
- Shielding plants from rain-splatter and in turn, keeping dirt and fungal diseases at bay.
Biodegradable mulching fabrics vs synthetic mulching fabrics
First off the bat: their plastic material, which isn’t exactly a beauty queen nor an eco-warrior.
Secondly, while durability can be a comforting thought for many, synthetic fabric impoverishes soil. In fact, it indeed favors plant growth for the first few years, but over time, soil loses its fertility. The reason behind this is that it’s no longer being fed organic matter, resulting in a lack of nutrients for plants.
This is where biodegradable mulching fabric comes into play.
The answer lies in the very name of this mulching method. Biodegradable! These mulching fabrics, also known as mulching felts or mulch mats, protect soil while nourishing it.
In fact, over time, they degrade, decompose and enrich soil because they are made from natural materials. These materials are compostable, recyclable, and keep micro-organisms and micro-fauna alive and kicking. And after a few years, they fully integrate into the soil, unlike plastic fabrics which often age poorly and break down into noxious micro-plastics.
Furthermore, these mulching felts are significantly more permeable to water and air than their synthetic counterparts. Runoff is reduced and rain penetrates better into the soil. Note, however, that synthetic mulching fabrics prove more resistant, including to foot traffic.
Diverse types of plant-based felts
Available in rolls, squares, or circles and with different gram weights which equate to thickness, these biodegradable mulching fabrics are made from various natural materials:
- Mulching fabric made from coconut fibers boasts a lifespan of 5 to 10 years.
- Hemp-based mulching fabric is a superstar when it comes to blocking out light. It’s great at retaining water and lasts 1 to 2 years, depending on soil and climate. The humus produced by hemp degradation doesn’t acidify soil.
- Mulching fabric made of jute or sisal: two fibers from tropical herbaceous plants, which, unfortunately, we don’t grow around here. Pretty thick, this fabric degrades in about 2 years. It’s a thermal insulation hotshot thanks to its density. Some fabrics can’t be used in organic farming as they contain a polypropylene film.
- Mulching fabric made from cornstarch is derived from the fermentation of sugar and cornstarch. It has a low density, making it light and easy to install.
- A linen-based mulching fabric is made from compressed or woven linen flakes. Decomposition happens in 1 to 2 years and creates a high-quality humus. This is a win-win!
You can also find mulching fabrics made from composite materials, a mix of different fibers, or even bioplastics or biopolymers, which are more for professional use.
There’s a hitch, though…
These biodegradable mulches win environmental respect points, hands down. However, depending on your needs, you might want to note a few drawbacks.
- By nature, these mulching fabrics are less durable over time, except for coconut fiber mulch, which boasts a lifespan similar to synthetic mulching fabrics. On the flip side, they’re more visually attractive and enrich soil as they degrade.
- They cost a pretty penny compared to synthetic mulch.
- These mulching fabrics aren’t as sturdy as synthetic ones, and may not take well to foot traffic.
- Installation can sometimes be difficult. For example, jute mulch is thick and can be quite a handful to manipulate and cut.
Plant-based mulch: yet another alternative!
Biodegradable mulching fabrics are efficient, but can be expensive and a hassle to install, especially over large areas. Various plant or organic mulches (Ramial Chipped Wood (RCW), flax shavings, hemp or miscanthus, hulls and cocoa shells, buckwheat hulls) are just as effective at keeping weeds at bay and limiting irrigation, and they’re particularly attractive and easy to apply.
Nonetheless, they don’t all share the same characteristics and can’t all be used in every flowerbed, border, or garden. For example, pine bark mulch should only be used for acid-loving plants.
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