Leaf mulch is a free amendment that we can use to improve the quality of our garden soil. As it decomposes on the surface, it slowly releases nutrients into the soil. Many people use leaf mulch to modify their sandy or clay soil because it adds organic material.
Mulch is also an excellent weed suppressant and it forms a barrier against the grass in your garden beds. It also helps to reduce unnecessary evaporation from the soil. Ultimately, leaf mulch will prevent weeds from growing because it stops light from getting to the surface of the soil.
What is leaf mulch?
Leaf mulch is a natural covering that we use on the surface of the soil to protect the roots of plants. Mulching leaves is a simple, very effective way to recycle leaves for use in your garden.
If you think about forest floors and other natural settings, you will see how the leaves from trees fall and create a natural carpet over the ground. Nobody clears the leaves from forest floors as we do in our garden environments.
Instead, they decompose naturally on the forest floor eventually creating compost. This organic material supplies trees and other plants with nutrients.
So, instead of bagging grass clippings and tree leaves, collect them and make your own mulch and/or compost. If you don’t have enough leaves, grab those that your neighbors have raked up, bagged, and left on the curb.
You will need to shred leaves before you use them as mulch to allow air and water to penetrate the mulch and speed up the decomposition process.
You can, of course, buy mulch from your local garden center, but it’s considerably cheaper and just as effective to manage leaves, collect them, and recycle them.
Can leaf mulch stop weeds?
The million-dollar question is, will mulch prevent weeds? And the short answer is, yes.
Leaf mulch can stop weeds from growing and multiplying. When you spread a thick layer of mulch around your plants it insulates and enriches the soil and smothers weeds.
The coverage also maintains moisture in the soil and can suppress weeds. Additionally, it provides a safe haven for earthworms.
Provided you spread the mulch properly, it will both prevent damage to plants and literally stops weeds from popping up out of the ground. It does this by blocking out the air and sunlight that weed seeds need to sprout.
Of course, the first step in preventing weeds by using leaf mulch is to make the mulch. The next is to weed the area where you plan to lay the mulch.
Hand weeding is the best way to be sure you get rid of all the weeds. Also, be sure to remove their roots.
How to prevent weeds using leaf mulch?
Texas A&M AgriLife Extension Service horticultural agent Skip Richter has some helpful advice that will help you prevent weeds with leaf mulch. He points out that “wherever sunlight hits the soil, nature plants a weed.”
His preferred method is to use a layer of newspaper on the soil surface before placing the mulch. This effectively creates a barrier between the soil and the mulch and stops the sunlight from penetrating it.
The other challenge is that, if the mulch is light, without a newspaper, some weeds can push right through it. His method is to lay newspaper over the moistened soil, splitting it where there are plants so they don’t get smothered.
Once the newspaper is in place, spray it with a little water and then place your leaf mulch on top of it. The only time weeds are likely to appear is if there’s a hole in the newspaper. If this happens, push back the mulch, pull out the weed, lay another small piece of newspaper over the hole, and then cover it up with mulch.
As he explains, the beauty of this technique is that it prevents weed seeds from germinating. If weed seeds do sprout, they will probably die and then decompose under the newspaper. This, in turn, releases valuable nutrients into the soil.
A group of horticulturists from Texas A&M Agrilife Extension offers tips on leaf management plans. This includes mowing light coverings of leaves when they fall on your lawn, making it easier to accumulate them for mulching.
They recommend a 3-6 inch layer of shredded leaves around the base of trees and shrubs. Use a little less (2-3 inches) mulch of shredded leaves in flower beds.
Vegetables do best when you place a nice thick layer of shredded leaves or grass clippings between rows.
They emphasize the importance of leaves as a valuable natural resource. Incredibly, leaves contain 50-80% of the nutrients that plants extract from the air and soil.
So, by managing fallen leaves rather than bagging them to be hauled to landfills, you can use them profitably in your home landscape.
What is the best mulch to prevent weeds?
Fallen leaves are the most common materials we use to make mulch. But we also use other natural materials, including tree bark, wood chips, straw, gravel, and even newspaper.
While gravel and shredded newspaper is exceptionally good at stopping weeds from growing, they don’t have the same mulching qualities that leave have. While gravel improves drainage, neither it nor newspaper will decompose and feed the soil.
But, as you have seen, using a layer of newspaper under leaf mulch can be an extremely effective way to prevent weeds from growing.
As the University of Florida’s Institute of Food and Agricultural Sciences (IFAS) points out, mulch is “the cornerstone of a great weed control program.” But there are many different types and the trick is to choose the best mulch to control weeds and stop them from growing.
They recommend organic mulches, of which fallen leaves and grass clippings are just one example. But it is certainly the most common one.
The only caveat is that organic mulches do decompose over time. That’s great because you end up with compost.
But it means that as it decomposes, the depth of your mulch layer will drop and weeds may start germinating again. When it falls below 2 inches it’s time to replenish your mulch.
If you are wondering if will mulch stops weeds from growing in your garden, this post should answer your question.
Ultimately, as long as you use a good, thick layer of leaf mulch and lay it properly, you can definitely stop weeds from growing in your garden beds.