How To Stop Weeds From Growing In Mulch

The problem of weeds in your garden isn’t something off the wall. Gardeners have been experiencing infestations since time immemorial.

One of the conventional ways of eliminating them in your garden is by mulching. If it works that well, what should you do when you notice weeds growing in mulch? Of course, you would be left scratching your head.

Should your burn down your entire garden to get rid of them? Of course not.

There are several ways to prevent weeds from growing through the mulch, such as using a weed barrier, thickening the mulch layer, and using herbicides and alternative mulching materials. Choose whatever suits your budget.

1. Put A Weed Barrier Underneath Your Mulch

One easy way to stop weeds from growing through mulch is to use weed barriers. They are usually available in local stores or can be purchased online.

The plastic material complements the efforts of your mulch material as a physical barrier against weeds. Given the many types available, we advise going for the black ones.

Clear weed barriers may help you see the weeds but aren’t that effective since they still allow light to pass through. That said, having clear weed barriers is more effective than having no weed barrier at all.

The question lingering in your mind right now is how your plants are expected to grow through them.

We advise strategic cutting of X shapes through the barriers. It works pretty well in a garden with plants growing from seed.

Cut around the areas the plants are supposed to grow, and everything will work out fine. You can then spread a layer of mulch on top of the weed barrier.

Use Old Newspapers As Weed Barriers

Some gardeners are environmentally conscious and wouldn’t want to use a non-biodegradable material.

In that case, we recommend using old newspapers as a weed barrier underneath the mulch. Besides, they are biodegradable and decompose, adding nutrients to the soil. 

This helps protect your garden against weeds while holding on to your environmental stance.

However, you will need to replenish them regularly compared to a commercially available weed barrier.

2. Thicken The Mulch Layer

Mulch in your garden helps in controlling weeds by denying them light. However, sometimes the mulch may not be thick enough to block the sunlight entirely. 

Weeds getting sunlight means they will continue to grow. How about laying more mulch?

Lay mulch that measures up to 2 inches thick to effectively block sunlight and prevent the weeds from growing. Replenish it regularly to cover for decomposition and the material getting blown away. 

3. Hand Pull Weeds

Let’s face it. Weeds are very resilient and will grow through your mulch at times.

Instead of using sophisticated methods, bend your back and step in the mud.

This typically involves hand pulling the weeds by their roots out of your garden. This could be quite tedious but is worth the effort.

Make use of a trowel to fasten the process.

Preferably, you should do this before well before laying the mulch to ensure they don’t resurface through it.

4. Stop the Weeds With A Herbicide

If hand pulling the weeds is quite strenuous for you, we advise using pre-emergent herbicides on your garden before laying the mulch.

You want to apply them in early spring before the weeds sprout. The pre-emergent herbicides won’t be as effective should you use them after the emergence of weeds.

Do this stepwise: 

• Rake off any mulch material aside. 
• Uproot or get rid of any emerging or pre-existing weeds. 
• Apply the pre-emergent herbicide following the manufacturer’s manual. Be keen on the label as some plants are intolerant to certain types of pre-emergent herbicides. 
• Carefully replace the mulch without disturbing the treated soil. 

After the above steps, you can add another layer of pre-emergent liquid herbicide on top of the mulch as an additional layer of protection.

Using liquid herbicide is ideal since it will stick to the mulch and remain potent.

You could also use a broad-spectrum herbicide like glyphosate to de-weed a heavily infested mulch area. However, using glyphosate requires extreme caution since the herbicide eliminates any broad-leafed plants it comes in contact with.

The trick is to apply it carefully using a paintbrush while avoiding nearby plants as much as possible. You can also use cardboard to protect the other plants during application.

Ensure the treated weeds are completely dry before removing the cardboard. For a more eco-friendly approach, consider using a mix of salt, vinegar, and dish soap to eliminate the weeds as they grow. 

5. Construct Borders Around Your Mulched Areas

Weeds growing in your neighbor’s lawn or flowerbed could very well spread to your property.

A border helps to prevent them from taking over your mulched areas.

Dig a trench around your garden and create a border using pavers, rocks, or bricks. These materials help prevent weeds from encroaching and growing through mulch.

Besides, they add aesthetic value to your garden. 

6. Water Only The Desired Plants And Not The Weeds

Another way to prevent weeds from growing in mulch would be to deny them water.

Like any other plant, weeds love water and denying them this precious resource eventually eliminates them. The drip irrigation system can best achieve this purpose since it only sprays water around the roots of your desired plants.

The weeds will suffer water stress and ultimately fail to sprout. 

7. Plant Ground Cover Crops

Plants that grow close to the ground can easily take care of the weed menace in your garden.

Weeds usually sneak into the space between your garden plants. Growing ground cover crops means that the weeds will have little to no room to grow.

Some suggestions include Catnip, Mint, and Rosemary. These plants also add to the overall aesthetics of your garden.

8. Use Alternative Mulching Materials

Sometimes alternative mulching material may prove to be the best choice.

For instance, you may want to use shredded bark for landscaping. It has a coarse texture and takes time to decompose.

It also doesn’t blow away easily, making it a good fit for blocking sunlight. Some other materials to consider are cocoa hulls, pebbles, and wood chips.

We advise against using certain types of mulch, such as grass clippings, leaves, and pine needles.  These decompose quickly, giving weeds time to sprout. What’s more, grass clippings carry seeds that add to the pool of weeds in your garden.

Wrap Up

Mulch is a great physical barrier to keep weeds away from your garden. However, it has its fair share of challenges and may allow weeds to grow through.

Fortunately, by deploying the methods above, you can stop the menace of weeds growing through your mulch.

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