Are Coffee Grounds Good For Grass? (Helpful Information)

Last Updated on February 15, 2022 by John Moretti

As society evolves and is aware of our impact on the environment, there has been a shift away from harmful chemical fertilizers and a drive to find environmentally sustainable gardening options. So are coffee grounds a potential solution for grass? 

If used correctly, coffee grounds can act as a slow-releasing fertilizer that improves grass, plant, and soil health. Coffee grounds, while an environmentally friendly and sustainable gardening solution, must be used sparingly and with regard to any wildlife present in an area. 

Although coffee grounds are good for growing grass and plants and promoting general soil health, the science alone is insufficient to improve yard health. Instead, the methodology of using coffee grounds needs to be adhered to for best results. 

Why Are Coffee Grounds Good For Grass? 

There is a misconception that the caffeine in coffee grounds improves yard, plant, and soil health. However, the truth behind the benefits of coffee grounds is far more complex and, in turn, provides a blend of nutrients needed for healthy grass growth.

Using ground coffee from Starbuck as a litmus test, it has been found that ground coffee contains 2.28% nitrogen, 0.6 potassium, 0.06% phosphorous, and a host of other minerals and nutrients vital to the promotion of grass and plant growth. 

Coupled with trace amounts of copper and magnesium, this complex blend of minerals and nutrients allows for a unique combination of slow, gradual fertilization over time and an immediate release of high amounts of nutrients to promote growth.

Therefore, coffee grounds provide a unique advantage over synthetic fertilizers, which generally only provide a quick boost to grass and plant growth while being unable to provide long-term absorption. 

Synthetic fertilizers also tend to be expensive, harmful to insects, animals, and water tables, cause lawn burn while posing a threat to long-term soil health, whereas the organic nature of coffee grounds results in little to no harm to the environment. 

For visualization of how coffee grounds release nitrogen into the soil to promote soil health, grass growth, and plant growth, the following is a link to Inside Science’s YouTube video “Coffee Grounds For Greener Gardens”: 

The following video comes courtesy of experiments conducted by the University of Arizona’s engineering department. 

Furthermore, the presence of coffee grounds promotes the attraction and health of earthworms. This is important as earthworms eat the grounds and other organic materials such as dead leaves. 

By doing so, the earthworms break up and aerate the soil, improving air and water circulation in the ground, while also facilitating beneficial microbial activity.   

How To Use Coffee Grounds To Improve Yard Health? 

Although the easiest method of adding coffee grounds to your lawn is to simply sprinkle coffee grounds over the grass and rake them into the soil, this is one of the most ineffective methods of utilizing coffee grounds. 

In fact, there may be some evidence to suggest that doing so could cause more harm than good as it may slow down growth or provide unnecessary obstacles for water to penetrate, meaning that absorption of water by the roots of plants is reduced. 

The reason is that by using coffee grounds by themselves, they lack the complimentary microorganisms needed to break down the grounds and release the micronutrients housed within. 

For this reason, coffee grounds should be coupled with compost or nitrogen fertilizer for maximum results. 

1. Coffee Grounds In Compost 

composting

Well-rotted compost has long been recognized as the best additive to grass and other plants to promote growth and soil health in an environmentally, efficient, and sustainable manner. 

A good compost mix not only adds nutrients to the soil but conditions the soil to your liking, helping it to either retain or release moisture; to achieve this compost mix, the following composure is recommended: 

  • One part dry leaves and other brown, organic material, 
  • One part fresh grass cuttings and pulled weeds, and 
  • One part ground coffee. 

Once mixed, this compost must be routinely turned every two weeks to allow for maximum heat exposure and rotting times. Provided this heat exposure is done correctly, it should create substantial usable compost within three months. 

When applying this compost, it is recommended that a hand-cranked fertilizer spreader be used to add a thin coat across a wide area, where after the area is watered to assist organic particles in moving into the soil. 

2. Coffee Grounds In Nitrogen Fertilizer 

nitrogen fertilizer

Should you opt to use nitrogen fertilizer on your lawn, coffee grounds should be used as an additive to encourage the growth of microbes in the soil. These microbes help break down the coffee grounds for maximum nitrogen release. 

It is vital that coffee grounds are applied to a damp lawn and raked into the soil with nitrogen fertilizer. Simply applying coffee grounds on the top layer results in the grounds drying up and preventing the absorption of moisture in the soil.

What Are The Dangers Of Using Coffee Grounds On Grass?

dog in garden

While coffee grounds seldom harm plants, animals, and insects, there may be instances where the use of coffee grounds may present a health hazard to pets or may attract unwanted animals to your yard! 

Beginning with pets, it has been well documented that both cats and dogs are far more susceptible to the negative effects of caffeine than humans. This means that care must be taken to ensure coffee grounds are thoroughly integrated with soil. 

Failure to do so may lead to complications, from mild to severe, for any animals that may consume large quantities of coffee grounds that sit atop the soil, rather than grounds that have embedded themselves in the soil and cannot be reached.  

Furthermore, while coffee grounds are a great way of repelling common garden pests such as slugs, snails, or squirrels, there have been reports of bears being attracted to gardens that use coffee grounds on their lawns! 

Caution should be taken to ensure coffee ground usage is not excessive or sufficiently integrated with the soil in rural areas where bears may be present.

Where To Source Coffee Grounds For Your Yard? 

shop

It is unlikely that ordinary household use will produce the number of coffee grounds needed to successfully use it as a substitute for synthetic fertilizer and chemical lawn treatments. 

Fortunately, many coffee shops and offices with industrial coffee machines simply dispose of their spent coffee grounds. This provides an opportunity to acquire some used grounds with little to no expense!

Conclusion 

Provided that coffee grounds are used correctly, and the necessary precautions are taken to not cause any harm to animals or the environment, they present a cheap, efficient, and environmentally friendly method of yard management.