Cardboard Weed Mat – Eco-friendly Weed Fighting Hack For Gardeners

Although most of the garden was beautifully under control, the weeds were not. Weeding was becoming a never-ending job and taking up far too much valuable time and it was clear a solution was needed. This is why I swear by using a cardboard weed mat and why you might need one too!

Posted by Shea on April 27, 2014

A cardboard weed mat is perfect for a garden that is in a complete state; overgrown, full of weeds and in this case, surrounded by a barely surviving lawn. When we purchased our home the overgrowth was so established there was enough soil on the roof of the chook pen to keep many earthworms contented. They were quickly shovelled off into the garden below.

It took quite a few weekends of ‘blood (there were many cuts and scrapes), sweat and tears’ to bring it back under control before slowly, but surely, we created some lovely little areas we are now proud of.

Although the garden required some initial hard work to clean up and rejuvenate, thanks to the cardboard weed mat the maintenance routine now is little to none. For our household this is the essential target which needs to be met, as time is just as scarce for us, as I’m sure it is for you.

This category ‘Eat, Throw, Grow’ is a work in progress as we continue to integrate our back garden and conscientiously reuse our household waste. Look out for future stories involving our chooks, composting, vegetable gardens, native bees etc…

Related Post: Recognising Native Bees

Cardboard Weed Mat and Mulch

Half a day every couple of years is my type of gardening…

It was during the final semester of my second pregnancy, back in 2012, that our garden was first dressed with a cardboard weed mat and mulch. The nesting urge hit hard during this pregnancy and getting the weeds under control became a top priority – looking at an unkempt garden drives me nuts!

The conversation regarding weed management was both with my Mother-in-law (who will from now on be referred to as Nanny) and the local cafe owner across the road. For although most of the garden was beautifully under control, the weeds were not. Weeding was becoming a never-ending job and taking up far too much valuable time – it was clear a solution was needed. Luckily Nanny came to visit and introduced our garden to mulch.

This was a great day.

Mulch is designed to retain moisture in the soil by protecting it against the sun and therefore evaporation. It smothers the weeds (which is one of the best things) and any that do happen to get through, are much weaker and easier to pull out.

Laying mulch worked a treat for most of our garden however, there were a couple of areas in which the weeds were continuing to push through seemingly undeterred. This meant tougher measures had to be taken and adding a layer of newspaper under the mulch was suggested.

So over the road to the cafe to see if they had a pile of out of date newspapers which could be used and low and behold the owner had an even better idea – cardboard. Much thicker and therefore offering extra resistance and longevity. He had a pile out the back ready to cart to the tip, so taking it was doing him a favour.

This was an even better day.

Fast forward to now, April 2014 and our Baby Girl has just celebrated her second birthday. The garden is beginning to look untidy and the weeds are reappearing, so it is time to set to work once again and lay the second cardboard weed mat.

Since the initial working bee two years ago, we have only had to add one top-up of mulch to the garden. This process has taken a previously ‘hard work’ section of our garden and turned it into a presentable, low maintenance area.

You have got to be happy with that!

This is how laying a cardboard weed mat is done…

YOU WILL NEED

Enough cardboard/newspaper to completely cover your chosen area.

You can either approach a local business or set aside your own household boxes instead of putting them into your weekly recycle bin. Remember to remove all tape and labels before you begin.

Mulch

We use Organic sugar cane mulch (there are so many options). The coverage on the bag says ‘9m2 if you lay it 50mm thick’ – use the calculations as a rough guide.

You might be surprised to learn that it is both the cardboard and the mulch which adds useful organic matter to the soil when it decomposes. After all, you are returning them full circle – from the ground, back into the soil.

PREPARATION

The ideal time to schedule in this job is after you have had good rainfall so there is moisture present in the soil to retain in the first place. Check the Bureau of Meteorology (BOM).

The mulch and cardboard need to be damp to begin the decomposing process and settle down the dusty mulch.

*Sneaky Short Cut

Good time management is to assign this project for a day decent rainfall is predicted. Working just before decent rainfall will save you both your time standing with a hose and conserve tap/tank water.

STEP ONE

Clear the area of any large weeds
Rake over the ground to roughly smooth the surface

STEP TWO

Lay the cardboard/newspaper over the designated area.

If you are using newspaper, build up a few layers to ensure the efficiency of weed prevention and longevity of coverage.

Established plants need to have enough clear room around the stem to allow water to easily reach the soil and ultimately the roots of the plant. A combination of tearing out holes in the cardboard weed mat to place over smaller shrubs (like putting on a jacket) and positioning the cardboard around the plants (like a jigsaw puzzle) works best.

If you are working on a day with no rain predicted, you will need to wet down the cardboard before laying the mulch.

STEP THREE

You can throw handfuls of fertiliser, broken down compost or manure on top of the cardboard weed mat

By feeding the soil during the decomposing process you encourage worm activity. Worms are super important as they aerate the soil, stopping it from compacting. This simple process sets up your soil for ideal growing conditions in the future.

Adding something heavy on top also keeps the cardboard from flying off in the wind or moving out of position – handy!

STEP FOUR

Spread your mulch

For a large garden, the easiest way is to carry the bag of mulch to the middle of the area, cut open the plastic and then the mulch can easily be separated. Check the manufacturer’s instructions for recommended safety precautions and how thick to lay your mulch. The thicker the coverage, the longer it lasts (which is the key focus here after all!!).

Remember to keep it away from the base of the plants.

STEP FIVE

Sit back and enjoy the results of your hard work – or if you’ve managed to time it right, get undercover out of the rain!!

The quality of soil in our particular area of the garden has had a significant improvement in quality since we first used the cardboard weed mat tecnique. Although no gardener, even I can appreciate the positive effect of having all this organic matter decomposing into the soil. It also gives me such a good sense of satisfaction finding a positive place to dispose of household waste, rather than adding it to landfill.

Nanny always says:

“If you look after the soil, the soil will look after you.”

I still have a lot to learn.

So that’s me done for another year or two. Garden looks loved again and there are no weeds – phew.

Now for the rain…