Grass Clippings As Mulch Pros And Cons ( Top 16 Pros and Cons )

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Mulching with grass clippings is not a new thing, in some parts of the world, this is an extremely common thing to do. Using grass clippings as mulch has a lot of benefits, although as with everything in life, it does have its fair share of cons as well. The good news is that there are way more benefits of using grass clippings as mulch than cons.

The major pros of using grass clippings as mulch are that it retains moisture stops weeds from growing and protects the soil from erosion. The grass clippings mulch will slowly add back nutrients to the soil feeding your plants. Some of the cons of using grass clippings as mulch are that the grass clippings tend to attract snails and slugs, in addition to this, it can’t really stop the quackgrass.

One of the main issues you will be having with using grass clippings as mulch will be with slugs and snails, my personal recommendation is to use a slug pesticide that is effective even after it rains Click here to check it out on

A lot of people are against using grass clippings as mulch, mostly because there are a lot of misconceptions about it. Usually, people will say that mulching with grass will deplete the nitrogen in the soil. This is completely false, as the bacteria will use the nitrogen from the grass clippings while decomposing, and there is plenty more nitrogen in the grass clippings which will get into the ground thus feeding your garden.

Although as a general rule you should never mix the grass clippings into the soil, as this will cause a nitrogen imbalance, and oftentimes it will do more harm than good.

Grass Clippings As Mulch Pros And Cons

In my experience, using grass clippings as mulch has both pros and cons to consider. On the positive side, grass clippings are readily available and free, making them a cost-effective option for mulching. They also provide excellent moisture retention, suppress weed growth, and gradually release nutrients back into the soil. Additionally, grass clippings can help regulate soil temperature and contribute to a healthier garden ecosystem.

However, there are a few drawbacks to be mindful of. Grass clippings can create a dense mat if applied too thickly, potentially hindering air circulation and water penetration. They may also contain weed seeds and could introduce chemicals if the lawn was treated. Furthermore, grass clippings decompose quickly, requiring more frequent replenishment. Considering these pros and cons, it’s important to weigh the benefits against the potential downsides and adjust your approach accordingly when using grass clippings as mulch in your gardening practices.

Grass Clippings As Mulch Pros

In my experience, using grass clippings as mulch has numerous advantages. Firstly, grass clippings are easily accessible and free, making them a cost-effective option for mulching. Secondly, they provide excellent moisture retention, helping to keep the soil beneath them moist for longer periods, reducing the need for frequent watering. Additionally, grass clippings act as a natural weed barrier, suppressing weed growth and minimizing the need for manual weeding.

They also gradually break down and release nutrients back into the soil, enriching it with organic matter and promoting healthy plant growth. Furthermore, grass clippings help to regulate soil temperature, keeping it cooler in hot weather and insulating it during colder seasons. Overall, using grass clippings as mulch not only reduces waste but also enhances soil health and plant vitality, making it a practical and eco-friendly choice for any garden or landscape.

Grass Clippings Retain Water

If your area has relatively hot summers then you have most likely noticed that the ground is relatively dry and almost nothing grows in these patches of dry soil. Even if you water these dry patches of soil you will still not see any improvement, mostly because the topsoil which contains the nutrients has been eroded away and you are left with a patch of compacted soil. The good news is that if you place grass clippings on these patches of dry soil you will slowly add back the nutrients into the ground which allows plants to grow.

So if you have dry spots in your lawn or in your garden then add grass clippings as mulch and slowly you will start seeing the results. In addition to this if you add grass clippings to your vegetables, then you will have to water them less frequently. After only a couple of weeks of adding the grass clippings around your vegetables, flowers, or fruit trees you will see that the soil below is constantly moist.

In order for the grass clippings to be able to retain moisture yous should add around 2-5 inches of grass clippings. If you use just a thin layer then the grass clippings will dry out extremely fast and will not be able to retain any water. If you are adding grass clippings to your vegetable garden make sure to leave a small space between the mulch and the vegetables, as the mulch can actually damage the plant if it is in contact with certain plants like tomato plants for example. Grass clippings can be also used for composting toilets, if you want to know in which state you can use them, then check out my recent article What states allow composting toilets? ( Top 8 States ).

You Can Directly Grow Vegetables In Grass Clippings

If you have heard of the Ruth Stout gardening method then you probably know that she was using hay as mulch instead of grass clippings. The good news is that grass clippings can be used the same way, just make a thick layer of grass clippings and you can basically grow any kind of vegetable or flowers that you want. The best part about this gardening method is that you do not even have to dig in your garden, and the extra nutrients from the grass clippings will be excellent for feeding your vegetables.

Grass Clippings Mulch Contain A Lot Of Nutrients

There are 3 main nutrients that are vital for most plants’ health, nitrogen, phosphorus, and potassium. These 3 nutrients will make your vegetables and flowers healthy, and a healthy plant has a higher chance of surviving fungal, or other pests that might attack it. The best part about using grass clippings as mulch is that these 3 nutrients will be absorbed into the ground in a matter of days or weeks.

Mostly because grass clippings are broken down by the bacteria relatively fast. The faster you get the nutrients into the ground the faster they will start feeding your plants. Wood mulch also breaks down and releases these nutrients but they take a very long time to break down. So if you have some annual plants then use grass clippings as mulch, and if you have fruity trees or bushes then use wood mulch. If you want to know how to make compost the right way then check out my recent article How to make compost at home step by step ( In 12 Steps ).

Grass Clippings Do Not Float On Water

If you have been using wood as mulch then you most likely noticed that once a heavy rain comes, the mulch simply floats away. Companies that make wood mulch often label their mulch as no float, although if you gave these a try you probably noticed that these do float. Grass clippings do not float away no matter the amount of rain, although there is a small trick to achieving that. Once you have placed the grass clippings mulch make sure to water it.

The water simply sticks the grass clippings together and after a couple of days, they will simply get stuck to the ground. If you are using old grass as mulch that has already dried up, then you can use the same principle, just splash some water on it and there you go.

Grass Clippings Smother Weeds

Grass clippings are excellent for smothering weeds, and this is the main reason why you should use a thick layer of grass clippings, especially in your vegetable garden. The thicker the layer of grass clippings is the more effective it will be against the weeds. Once you start using grass clippings as mulch you will notice that your de-weeding time has been significantly reduced. By significantly reduced I mean you will most likely have to do it once or twice a month.

Now, this doesn’t mean that some weeds will not get through, but the few of them that will come through the grass clippings will be extremely easy to see. The days of shoveling out weeds are over, as due to the grass clippings mulch the roots of the weeds will most likely grow in the mulch rather than in the soil, so you will have an extremely easy time de-weeding. With that being said there is one weed that can’t be stopped by grass clippings mulch, in fact, it can’t be stopped by any kind of mulch, this weed is the quackgrass.

Growing Seeds In Grass Clippings Mulch

It is possible to grow seeds with grass clippings mulch, but there is a catch. You will have to make space in the mulch and place the seeds in the ground, make sure not to cover the area where the seeds are, as they will most likely not be able to penetrate the mulch. In addition to this make sure that the seeds have plenty of space between them and the mulch, a couple of inches will be ok. If done correctly the nutrients from the grass clippings mulch will feed the seeds, and the plants will grow tall and healthy.

Grass Clippings Mulch Protects From Soil Erosion

When people think of soil erosion they think of a barren desert and odds are that you have probably already noticed this process in your garden or lawn already without knowing what it is. Once the top layer of soil has been eroded, mostly by rain and wind, it will not be able to absorb the water. This is why in many desert areas one of the most devastating natural disasters are floods. As the water can not be absorbed by the soil, it will simply run off, in any direction it can.

You have probably seen a couple of places in your garden where the soil is dry and even cracked, even though you get plenty of rain in your area. This is especially problematic for people who want to have a spotless lawn, and most of them will simply try to reseed these areas but it will simply not work. The soil in the areas where it is eroded is so compact that almost nothing will be able to grow in it.

By using grass clippings as mulch you give a chance to the eroded soil to recover, grass clippings are excellent for retaining water and as they decompose they will add back the nutrients to the eroded soil. Basically, you will be making another layer of topsoil to the eroded one. Just keep in mind that this does take some time to work, so make sure to add grass clippings mulch to the areas where the soil has eroded fairly often.

Grass Clippings Build Soil

There are a lot of people who use monocultures, which means that they grow one type of plant every year. As these plants take out a lot of nutrients from the soil, most farmers will till their farms and use fertilizers in order to aerate and rejuvenate the soil. The problem with this approach is that every year their soil is becoming less and less nutritious for the plants. The fertilizers do work but they do not bring in the beneficial bugs, critters, and bacteria that a lot of plants need, maybe that is why a lot of store-bought vegetables have no taste.

By using grass clippings as mulch you will be able to build soil, in such a way that there will be a natural balance in your soil. Worms, bugs, and critters will live in the mulch, and as they are breaking it down they will release the nutrients for the plants to use. Worms especially are important as they will help with nitrogen and with the aeration of the soil. If you are growing blueberries then it is extremely important to build soil correctly, if not your blueberry bushes will suffer, for more information check out my recent article Blueberry Leaves Curling ( Top 5 Reasons ).

Grass Clippings Protect The Soil From Drying Up

If you have ever dug up an area in your garden to plant some plants then you have probably noticed that after a couple of weeks, the topsoil has dried up. Although this is relatively good as no weeds will grow in these areas, but it is not healthy for the plants. By using grass clippings as mulch you will make a protective layer on the soil, this way the sun doesn’t come in direct contact with the soil and the grass clippings will retain the moisture close to the topsoil.

Grass Clippings Protect Bulbs From Frost

There are some plants that have to be planted in the fall, mostly because they need some cold to germinate. The problem is that in some years the winters tend to be colder, and even destroy the plants or their bulbs. If you place a thick layer of grass clippings in the fall above the bulbs then the chances of the bulbs actually surviving the winters increase significantly.

A little bit of storytime, I live in Alaska, and one of my wife’s favorite flowers is the gladiolus flower. These come in bulbs which then sprout out of the ground after a couple of weeks. One year I decided to bury the bulbs relatively deep so I don’t have to dig out the bulbs once the cold temperatures come. Added a thick layer of grass clippings on them and the next year in the spring some of the gladiolus bulbs have sprouted.

Grass Clippings Are Free

Most people who have a lawn will invest a significant amount of money into fertilizers, and a lot of work for making their lawn look good. Only to cut the lawn down and throw away the grass clippings, basically, they are throwing the money out. Instead, you can simply use the grass clippings as mulch, this way even when the grass clippings have been cut down you will “reinvest” your money’s worth into using it as a fertilizer and a weed killer around your precious plants.

Grass Clippings As Mulch Cons

From my personal experience, there are a few drawbacks to using grass clippings as mulch. Firstly, grass clippings can create a dense mat when applied too thickly, which can hinder air circulation and water penetration, leading to potential issues such as mold or rotting of plants. Additionally, grass clippings may contain weed seeds, which can germinate and create more weed problems in your garden.

It’s also important to consider the source of the grass clippings, as they may contain herbicides or pesticides if the lawn was treated with such chemicals. Lastly, grass clippings decompose relatively quickly, meaning that you may need to replenish the mulch more frequently compared to other types of mulch. While grass clippings can have their benefits, it’s important to carefully consider these potential downsides and use them judiciously in your gardening practices.

Grass Clippings Mulch Will Attract Slugs

One of the biggest cons of mulching with grass clippings is that it attracts slugs and snails. This happens because the grass clippings are excellent at retaining water, and slugs tend to love this environment. Basically while using grass clippings as mulch you are making an extremely comfortable living area for these pests. Not all people will notice more slugs, as the slug population in a specific area is mostly determined by the annual rainfall.

The good news is that slugs and snails tend to eat the decaying grass clippings, and for the most part, you will notice that your vegetables or flowers are not at all affected by the slugs. If the slugs are becoming a problem in your vegetable garden due to the grass clippings,  then you probably should use pesticides.

Grass Clippings Mulch Could Contain Pesticides

If you are using your own grass clippings then you shouldn’t have a problem. But far too often I see people recommending others to pick up other people’s grass clippings once they have thrown them away. The problem with this approach is that you never know if the lawn has been treated with chemicals or not. If the grass clippings do contain pesticides and you use them as mulch you will simply stunt the growth of your plants, or in the worst-case scenario outright kill them.

Grass Clippings Can Damage Some Plants

I often see a lot of people making the mistake of piling the grass clippings onto a plant, while this seems like a good idea, but trust me it isn’t. As the grass clippings mulch is starting to break down it will release a lot of nitrogen, and some plants can not handle this excess nitrogen especially if it is in close contact with the stem of the plant. In addition to this, as grass clippings are excellent at holding moisture, you might notice some fungal growth on the plant.

So if you are using grass clippings as mulch, make sure to make a small circle around the plant which you want to feed with the mulch, in such a way that the mulch is not in direct contact with the plant.

Grass Clippings Mulch Containing Weed Seeds

If you have grass clippings that do contain weeds then you will inevitably help to propagate the weed seeds. Some weed seeds will be able to germinate while they are in the mulch, but not a lot of them. I personally use grass clippings that do contain weeds and probably their seeds as well, and for the most part, I don’t have any problems with weeds at all. Even if your grass clippings only contain grass, some weed seeds will inevitably end up on them, flown in by the wind.

Grass Clippings Much Can’t Stop Quackgrass

Quackgrass is one of the most widely spread weeds in the world, and getting rid of it is almost impossible. If you want to use grass clippings as mulch to stop quackgrass then you will have a relatively hard time. The main problem with quackgrass is that it has several ways of reproducing and even cloning itself. Quackgrass in addition to producing seeds will also send shoots out both above and below the ground.

These shoots have a relatively strong tip, which allows them to go right through the mulch. Getting rid of quackgrass is especially problematic as you will have to take all of them out, and if you miss just one piece of a quackgrass shoot, then it will be able to regrow in a matter of days.

Key Takeaways

  • Applying grass clippings as mulch helps retain soil moisture, reducing the need for frequent watering. Additionally, the thick layer of grass clippings can act as a weed barrier, suppressing weed growth in garden beds.
  • Grass clippings contain valuable nutrients like nitrogen, potassium, and phosphorus, which can provide a natural fertilizer boost to plants as they decompose.
  • When grass clippings decompose, they can generate heat, which may harm plants if applied in thick layers. Moreover, if the grass clippings are left in a thick, wet pile, they can produce an unpleasant odor.