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Does Mulch Kill Weeds? (Plus Pre-Mulch Options That Help)

Does Mulch Kill Weeds? (Plus Pre-Mulch Options That Help)

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If you’re trying to kill weeds in your yard or prevent them from growing, mulch is an environmentally safe and effective option. However, it does work best when combined with one or more other measures of prevention.

In this article, you will learn about how you can utilize cost-effective, natural wood chips, or mulch, to keep weeds out of your yard.

As a bonus, not only will the mulch prevent unwanted plants from taking over, but it will also keep the temperature of the soil underneath it regulated and consistent, as well as trap moisture in the soil.

How Mulch Kills Weeds

Mulch kills weeds in a couple different ways. It both suffocates them and keeps adequate sunlight from reaching them, in turn killing many of the smaller plants.

It also helps prevent seeds of various weeds that are spread around by animals and wind from getting into your soil. In other words, it acts as a shield.

If you have put mulch down in the past and there are still weeds growing through the chips, it indicates that the mulch layer isn’t thick enough. It must be at least two to three inches thick to block sunlight from reaching any undesirable seeds that might be lurking in the ground.

Using a thicker layer also helps fill in more gaps in the mulch that lead to the soil, lowering the risk of a seed getting through. It really is true that life will always find a way to survive, so don’t let a seed take hold in the soil to begin with.

It can be tricky figuring out which type of mulch you should use. There are almost countless options available these days, and they all have different qualities that can be appealing for various reasons. You will need to do a bit of research to find out which is best for you.

It can be said that, unlike inorganic mulch, an organic kind will provide your soil with nutrients. Thus, this might be the best option for you as far as that’s concerned.

Pre-Mulch Options

Prior to laying the mulch, there are a couple things that you should consider doing. Some other preventative measures exist that you can combine with the mulch laying. Including these as well should make it even easier to manage the weeds in your yard.

Before you do anything else, make sure to pull any weeds that are present. You may be able to skip this step if the weeds are small with relatively shallow roots as the mulch should sufficiently smother them to death.

It is important to pull the weeds out at the roots to keep them from growing back. You can use a trowel to help you dig deeper down into the soil.

You should always think ahead when attempting to control weeds. It is best to take care of preventative measures before all the plants start growing in the spring. Thus, you should carry out all of these steps in the early spring for the best results.

Pre-emergent herbicide

Using a pre-emergent herbicide on your soil before adding mulch can dramatically affect how many weeds end up growing. It is advised that you use a natural herbicide for this step.

Keep in mind that this is only a preventative solution and will not kill any existing weeds it comes into contact with. That is precisely why pulling the weeds with the deeper roots before its application is vital.

After you apply the pre-emergent herbicide according to the instructions on its container, carefully lay down your two to three inches of mulch, being careful to avoid moving the soil around too much so as to keep the herbicide evenly applied.

Once you have added the mulch, you can protect your yard from weeds even more effectively by adding an additional layer of herbicide on top of the mulch.

Make sure that you use the liquid variety of herbicide if you add some on top of the wood chips. This will ensure that the solution soaks into the mulch and stays there.

Plastic, fabric, or paper covering

Another way to keep weeds from growing underneath your mulch is by putting a protective cover made of fabric or plastic over your soil.

You can choose a cover that is black and layer it in mulch completely to keep any parts of the material from being seen.

If you want to use a biodegradable solution, you can lay down a few layers of newspaper instead of a plastic or fabric cover. The downside to using paper, however, is that you will need to add fresh layers every so often as the newspaper starts to break down.

No matter what the material is, using a cover is an amazingly effective solution, especially when complemented with a pre-emergent herbicide and a thick layer of wood chips. This will undoubtedly keep far more weeds from sprouting up since it is another layer suffocating weeds and another barrier keeping seeds and sunlight out.

The only real negative aspect of using this preventative measure is the fact that any weeds that might end up coming through will be quite difficult to pull out of the plastic or fabric, especially at the root.

If you do decide to go this route and lay down a cover before spreading out the mulch, it is a smart idea to clear the soil of anything that could puncture the material, such as rocks, twigs, and other jagged objects. This is especially important if you are using a plastic or paper covering.

You can use a rake to sift through the soil and remove any risky items from the soil. This may seem like a lot of work just to put mulch down, but it will most certainly pay off in the end when you notice few to no weeds breaking through your layer of mulch.

It is ideal for you to use all three options when targeting weeds. It can save you a great deal of frustration in the future as you will be spending much less time pulling weeds out of your yard.


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