Will Coffee Grounds Kill Your Grass or Protect Your Lawn?

Will Coffee Grounds Kill Grass Cover (1)

As someone who loves to garden, I use coffee grounds on my lawn at least once per week. Coffee grounds are great environmentally friendly plant food. They also contain a considerable amount of nitrogen, potassium, and phosphorus. These are good reasons to trust the grounds while gardening, yet they can have costly repercussions to your lawn if not applied carefully.

Used coffee grounds will not burn your grass, instead, they will act as a natural fertilizer. Fresh coffee grounds are slightly acidic, and if used directly, they can dry your grass. However, these grains are valuable while getting rid of weeds since they dehydrate the sprouts even before they establish.

Coffee grounds are best for the garden after being used in your kitchen; otherwise, they have adverse effects on your grass. Once you’ve finished brewing your morning cup of joe, sprinkle your used grounds on your lawn or in your garden. Once per week is enough to provide your plants with healthy nutrients. They also keep certain insects, such as ants, away from your plants.

Using freshly ground coffee beans on your grass is a bad idea. Coffee is naturally acidic and will cause yellow or dark brown stains on your lawn. It will dry up the root system of the grass instead of feeding it valuable nutrients.

Instead of using fresh coffee grounds as lawn fertilizer, I use them to kill weeds. It’s a fast working, completely natural solution to some pesky plants that need to be attacked at their root.

The drying of roots occurs when the coffee, when exposed to air, dries up to form dense clamps or solid mass. Clamping prevents moisture from reaching the weeds, thus solving the problem quite early.

How Do Coffee Grounds Help Grass Grow?

Looking for an eco-friendly way to dispose of your coffee grounds after a nice cup of coffee in the morning? Always add them to your compost mix since, at this stage, they are still perfect for activating healthy plant growth.

In addition, these coffee grounds help maintain a warm temperature in the compost, which is great for decomposing bacteria.

Once per week, you can skip your compost bin and distribute the coffee grounds across your lawn and garden.

Nutrients in the coffee grounds are broken down, making absorption to the soil and into the grass quick and easy.

Coffee grounds also enhance biological activity within the soil matrix. They are readily edible to earthworms in the soil due to their nutrients. The worms consume them and aerate the earth with their castings, thus encouraging further microbial activity, which helps break down coffee grounds into nutrients.

This aeration assists in separating the clamped solids hence allowing moisture into the soil if an individual has subsequently used coffee grounds in their grass.

This process where the coffee is worm food, whereby worms leave air spaces during the process, is called vermicomposting.

Will Coffee Grounds Kill Your Grass or Protect Your Lawn 2

Pros and Cons of Using Coffee Beans on Your Grass

Fewer Insects

The remaining caffeine in the coffee grounds helps to keep pests such as slugs and snails from the grass. The caffeine smell is disgusting to some of these animals, which works well in your favor during a barbeque cookout.

Keeps Stray Animals Away

The smell of coffee is enough to keep cats away from your lawn, as they are repelled at the farthest sniff. In addition, using coffee grounds at the borders of grass yards under lawn grass pushes them from hanging around anywhere close to that area.

Kills Fungus

When strikes of fungi attack your beautiful lawn, they cause ugly patches on the grass, making it look unkempt, a sore sight. Sprinkling ground coffee and raking it in the grass causes the disappearance of these fungal pathogens, protecting the grass from severe attacks simply from your kitchen.

So far, so good, we realize that coffee grounds will not necessarily kill your grass, but that doesn’t mean it will gradually steal vitality and life from your green carpet. A couple of the downside of using excessive use of coffee grounds are;

Dry Grass

If you are used to sprinkling the coffee grounds straight from the kitchen without further care, chances are you created a layer block on top of the soil. Clamping leads to no moisture penetrating the soil either because the dried-up coffee layer sucked it in or evaporated while still waiting to enter. Within a week or two, your grass will be turning yellow and ugly.

Affects Soil pH Levels

Excessive usage of coffee grounds also leads to changing soil pH to a higher level. As stated earlier, the pH of coffee is almost a level higher than the required amount for grass. High pH levels lead to the burning of the grassroots and eventually affecting the overall health of your lawn.

Do Coffee Grounds Kill Weeds?

Yes! The coffee grounds are actual weed suppressants, especially when they are damp and straight from your kitchen. When added to the compost mix, they increase the temperature of this mix, thus speeding up decomposition.

When mulching grass at soil level with compost mix, the heat kills weeds instantly in their sprout mode and other pathogens. Coffee grounds also have allelopathic properties, stunting their germination properties in the weeds, hence making them die at this stage.


All in all, coffee grounds are a very much essential accessory to a gardener because one reuses a commodity from your kitchen after kick-starting your morning.

They are in their best nature at this stage since they are damp and add moisture to your dry compost mix. In addition, they assist in creating better mulch which provides nutrients such as nitrogen and phosphorus to your grass.

These nutrients are essential in robust leaf growth, which is a suitable replacement for artificial fertilizers. They are also organic fertilizers, thus reducing soil pollution and unwanted fumes as caused by store-purchased fertilizers.

I also advise sprinkling coffee grounds to your lawn in small portions as they take a considerable amount to break down in nutrients.

Waiting in between application turns before sprinkling allows you to save up used coffee grounds before mixing them in your compost, increasing its efficiency in your lawn.

These grounds are best for your property after completely being broken down because they are easily absorbed. In conclusion, taking appropriate measures, coffee grounds won’t kill your grass.

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