Traditional black weed mat is not good for your garden. It ‘sours’ the soil by preventing proper airflow and water absorption, compacts clay and disrupt the soil food web.

Then, after a year or so, you will find weeds growing through the mat. With their roots firmly lodged in the weed mat itself, they become harder to remove and soon you find that what you have is now a mat made of weeds!

The photo below shows this effect on soil. Over the years mulch and soil have built up on top of the weed mat creating a lovely healthy hummus, rich with worms, roots and life. However this layer is cut off from the rest of the soil by a thick layer of plastic weed mat. Below the weed mat where water and airflow is restricted, we get compact, grey clay, which is much harder for plant roots to grow through, and very slow draining.

I recommend using a nice thick layer of bark, straw or mulch to suppress weeds and ‘feed’ the soil. This mulch will certainly reduce the amount of weeds that grow, whilst allowing air and water to cycle through; it will also encourage worms, beneficial insects, and microbes which work together in giving you much healthier soil and plants.

What if you need a little more help with weed suppression though? There are now quite a few alternatives you can lay on your soil before adding mulch, to help keep weeds at bay.

Traditionally we have recommended using a layer of cardboard or six-eight sheets depth of newspaper, which will form a breathable barrier long enough to kill off weeds, but will break down over a few months adding carbon to the soil. Make sure you cover the bed completely and wet the soil and the cardboard or paper before adding the mulch on top.

Several of my clients swear by the wool linings they get in their food boxes, and indeed in organic gardening old wool carpets are routinely used as weed mat, and even tasked with killing off tough weeds such as kikuyu.

Nowadays you can purchase eco-friendly weed mats such as wool mat or even coconut fibre mats from DIY stores and garden centres. These products will help keep the weeds away without harming your soil the way older ‘traditional' weed mat does.