Growing Microgreens In Coffee Grounds

growing microgreens in coffee grounds

Are you wondering if growing microgreens in used coffee grounds can result in a good harvest? Is it better than soil?

Growing microgreens are one of the easiest and quickest way to become a gardener. All you will need is a little space, some time, and a little gardening skill. In a matter of few weeks, you can grow your own nutrient-dense and tasty food.

There are many ways to grow your micro greens. If they are hydroponic, you can grow them in water. Also, you can grow them in soil, coconut coir, and even coffee grounds.

Or, are you someone who loves to sip on coffee now and then? So, you must be wondering what to do with all the old coffee grounds. We suggest you use them to grow your own nutrient-rich food.

Numerous plants can thrive in the nutrients provided by coffee grounds. Moreover, micro greens can do far better than most of them. So, if you are looking for an alternate medium to grow micro greens, you can always go for coffee grounds.

This article is written to walk you through answers to all the questions regarding growing microgreens using coffee grounds. Read on to learn some tricks and imbibe some more tips to grow your own greens.

Growing Microgreens In Coffee Grounds

Coffee grounds are similar to soil in resemblance as well as numerous other qualities. They both possess the nutrients required by the microgreens to grow healthy.

However, the type of nutrient and their quantities vary in large degrees. This is the reason why microgreens can thrive with the help of coffee grounds, but not in only coffee grounds.

Also, coffee grounds are more acidic than soil which is good for growing mushrooms. However, microgreens do not require the amount of acidity fungi do.

Microgreens are delicate, and the nutrient balance is crucial for their growth. Hence, a mixture of coffee grounds and garden soil can be an effective medium. So, yes, you can grow microgreens in coffee grounds, but only as a combination of soil and coffee grounds.

What Are The Key Nutrients In Coffee Grounds?

It is common knowledge that coffee beans contain caffeine that can keep a person awake and energetic upon consumption. However, the other constituents are not so well known. Some of them include magnesium, chromium, and free amino acids.

Here is the list of nutrients found in used coffee grounds that are beneficial for microgreens. Scroll through this article to understand why they are essential for the growth of microgreens.

1. Calcium

Calcium helps in plant growth by aiding in the production of plant tissues. It also strengthens the cell walls of the plants, which will, in turn, make the plant stronger.

Calcium also plays a major role in activating the necessary enzymes that can help coordinate cellular activities. It also helps in the plant’s response to stimuli.

They help a healthy soil structure as well as increase the water-holding and nutrient-holding capacity of the soil. This will stabilize the nutrient supply to the microgreens growing in it.

Although calcium deficiency is rare in soil, coffee grounds can provide it if there is a deficiency. 

2. Magnesium

Magnesium is the most important mineral required for microgreens. It is a crucial mineral required during photosynthesis since it helps in enabling the plants in capturing sunlight.

Magnesium is the central atom present in the chlorophyll molecule. Chlorophyll molecules are the pigment that makes the plants green, which will allow to them capture sunlight.

It is located in the heart of the chlorophyll, allowing activation of the enzymes required to produce energy. Magnesium deficiency can occur in garden soil, and coffee grounds can compensate for it.

Shortage in magnesium can lead to stunted growth in microgreens. However, the magnesium present in the coffee grounds can aid in their capability to grow.

3. Chromium

Chromium can be an excellent stimulator for promoting growth in microgreens grown in potting soil. It increases the biomass of the plants when it is low in concentration. This will boost the growth of microgreens.

However, a higher level of Chromium can have the opposite effects; it will decrease the biomass of the points. The higher concentration of Chromium can stunt the rate of growth at seed germination.

Chromium can be a high pollutant and harm the health of microgreens. However, it is found at an optimal level in old coffee grounds. It does not cause any harm like that of industrially manufactured chromium.

4. Potassium

Potassium is an essential component that aids in providing plants with balanced nutrition. It will help your microgreens use water in the right amount to sustain their requirements. They also promote the growth of healthy and green stems.

It is commonly found in potting soil. However, potassium deficiency can cause symptomatic issues in microgreens. Potassium also regulates the full growth of all the parts of a plant; this will ensure that every part is fulfilling in nutrition.

It is also one of the key ingredients in synthetic garden fertilizers NPK. Coffee grounds contain this in abundance. Hence they can act as fertilizers as well.

5. Nitrogen

Nitrogen is key in determining the growth rate of any plant. It is also essential for the development of microgreens and their reproduction. Nitrogen deficiency is widespread among plants.

It is vital for your microgreens because it is a major component of chlorophyll alongside magnesium. It also an essential component that builds the proteins in the microgreens.

Nitrogen is also a crucial component in energy transfer compounds. It will allow the cells to store and use the energy released during photosynthesis. It also helps your microgreens sustain by aiding in growth and reproduction.

The quantity of nitrogen in the coffee grounds will supplement the growth of your microgreens. It also will help them grow to the fullest with a maximum amount of nutrition.

6. Iron

Iron aids in the energy production of plants. It is essential in the formation of chlorophyll. It primarily helps in the movement of oxygen through the parts of roots, stems, and leaves.

It is also essential for the functioning of enzymes in your microgreens. This will help in the proper metabolism of the plants. Coffee grounds can provide an adequate level of iron for your herb.

Iron is a micronutrient for plants, which is less significantly necessary than macronutrients. However, an iron deficiency can cause the leaves to lose their pigment; it is called chlorosis. Mixing coffee grounds with soil can prevent this.

7. Phosphorus

Phosphorous is a key component that can help in vital plant functions. It includes the transfer of energy, conversion of sugars and starches, and photosynthesis. It is also involved in the movements of components in the DNA.

ATP is called the energy unit in plants. Phosphorous is an important component of ATP. It is essential for your greens from the germination of the seed to its maturity.

It is a vital component that can decide the overall health and energy of your microgreen. Besides, it can stimulate root development, improve stalk and stem strength, and increase resistance to diseases.

Since phosphorous can move around in the plant body easily, a deficiency can be easily translocated. This tends to make the problems worse from bad.

Hence, it is vital to make sure your microgreens are getting enough phosphorous. Coffee grounds can help you with doing so.

8. Acids

Coffee grounds are known for their acidity. It may seem like acids present in it can only harm the plants. However, it is not true.

Acids such as fulvic acids or FA and humic acids or HA are natural compounds found in soil. They are also found in potting soil. They can bring numerous chemical and biological benefits to your microgreens.

These components are called plant bio stimulants since they can enhance the vigor and growth of plants. It can do so without having to kill any pests.

They can also increase the quantity and quality of the harvest. These components in coffee grounds can increase tolerance in plants towards weather, diseases, and pests.

These components can prevent the soil from leaching out. These acids can also increase the uptake of nutrients in microgreens.

Some of the biological benefits of these acids in coffee grounds include hormone regulation and cell division.

Moreover, the ph level is optimal in coffee grounds. This can make coffee grounds an excellent medium for growing microgreens.

9. Polysaccharides

Polysaccharides are primarily functional in the storage of energy. It can support the plant tissues to stay firm.

The polysaccharides function as a regulator in numerous physiological processes. These processes include morphogenesis, time of maturity, rooting, and cell wall formation.

Their main purpose is to provide the herb with the required protection and energy. Plant cell walls are made of two major polysaccharides known as cellulose and hemicellulose. They provide the required rigidity in plants.

These polysaccharides are found in coffee grounds; this will help grow sturdy micro green anywhere you want. They are also essential in the formation of macromolecule compounds. It includes cellulose, glycogen, starch, and peptin.

10. Carbohydrates

Carbohydrates are essential for the growth of microgreens since it an essential energy source. It provides carbon skeletons for storage components and organic compounds. They play an interesting role in plant immunity as well.

Similar to human beings, greens also possess an immune system that helps them in fighting against diseases. Microgreens need carbohydrates to prevent them from pathogen cells. They do so by interacting, making diurnal changes, and hormone signaling.

Various kinds of carbohydrates affect the immunity of microgreens in different ways. Hence, they must be provided with all the necessary carbohydrates in the required amounts.

Coffee grounds can provide an adequate level of carbohydrates that are essential for microgreens.

11. Tannin

Tannins play a major role in protection from infections caused due to fungi or bacteria. It is a naturally occurring protein usually found in flora.

They possess a binding quality that can reduce numerous toxic effects. It can reduce the effects of pollutants coming in contact with microgreens.

They directly help the microgreens by removing harmful bacteria, fungi, and even viruses. Coffee grounds are abundant in tannin, which makes the grounds perfect for the prevention of diseases.

12. Thiamin

Thiamine is a component that is an activator for disease resistance. Additionally, it works as a supplement for the support provided by carbohydrates.

It protects from both abiotic and biotic stresses for plants. The disease, as well as stress protection, contributes to the better growth of microgreens.

Coffee grounds contain a high level of thiamine. Hence you can see amazing results with the help of this component.

What Types Of Coffee To Use?

If you have been worried about the type of coffee to use for growing microgreens, you do not have to. This is because all the nutrients present in regular coffee are also present in decaffeinated coffee grounds.

Although decaffeinated coffee grounds work just fine, you must ensure to remove caffeine from coffee beans. You can use chemical solvents that are available in online and offline stores.

However, there are chances of residue being left behind in the coffee beans. This can negatively affect your results of growing organic microgreens using coffee grounds.

Also, the type of coffee may affect the color and the rate of growth of microgreens. However, the effect will not be significant.

How To Store The Coffee Ground?

It may seem like an easy task to store coffee grounds in a container; however, if you store it randomly without worrying about any mold. You may end up wasting a lot of coffee grounds.

Coffee grounds are highly acidic in nature, and fungi like to grow in them. Hence, if you fail to store it properly, the container will be filled with mold.

Following is a step by step guide to ensure the coffee grounds are stored correctly.

  • Take out all the coffee grounds present in the filter of the coffee maker.
  • Do not dry them.
  • Store them in a sealable plastic bag or any other air-tight container.
  • Place the bag in the refrigerator.

As long as the container is airtight, it is ensured that there will be no formation of mold. However, if you place them for a long period, there are chances of air entering the bag. This can lead to the formation of mold on the coffee grounds.

Benefits Of Coffee Grounds

There are numerous advantages to using coffee grounds. Some of them are listed below.

1. You Can Fertilize Your Garden Using Coffee Grounds.

Coffee grounds can be used to fertilize your garden. They contain several vital components that are essential for the growth of your microgreens.

They can also attract the necessary worms that will enrich the soil with more nutrients. You can use it with other compost material and fertilize your garden whenever necessary.

2. It Can Repel Pests And Insects

Caffeine and Diterpenes present in coffee grounds can repel harmful insects. This is due to the toxicity these chemicals possess for insects and bugs. This includes fruit flies, mosquitos, and beetles.

Slugs can tear the microgreens and have large holes in them. Also, they leave a harmful slime trail. Coffee grounds can keep them away since they are repelled by their smell.

3. Neutralize Soil

If the potting soil contains less acidity, you can always use coffee grounds to fix it. This neutralization can help your microgreens thrive in the optimal environment.

4. It Can Help Aerate The Soil

Coffee grounds can aerate the soil and improve drainage if added in the right amount in regular intervals. Soil can improve aeration when it is filled with any organic matter. This will allow the roots to absorb better air, nutrition, and moisture.


Coffee grounds are pretty acidic in nature. If you rely on them alone, the roots of your microgreen may die soon. If you are not careful about the quantity of the coffee grounds, more chances are to do more harm than good.

Also, if you simply sprinkle coffee grounds over the surface, they can form a thick layer. This will create a barrier that can prevent the essential water from reaching the bottom. In some cases, excess caffeine can hinder the growth of seedlings.

How To Mix Coffee Ground With Soil?

Coffee grounds are mixed with soil to reduce the acidity of coffee grounds. It is necessary since a high level of acidity can cause damages to the roots.

You will have to combine equal parts coffee grounds with equal part potting soil. You can also add some dried leaves or any homemade compost with it. Add this mixture to your garden or in your planter.

Always make sure that you are not adding too many grounds since it can increase acidity. So, supply a limited amount of ground. Or, you can also sprinkle meticulously on top of the surface to avoid adding too many grounds.

Things To Remember While Growing Micro Greens With Coffee Grounds

To lessen the chances of harming the growth of your microgreens, course along with the following points.

1. The Soil To Coffee Ground Ratio

The soil to coffee ground ratio is a crucial factor to take care of. If you want good results, this factor is something you should not overlook.

If the coffee grounds are more, you may risk killing the microgreens by burning their roots. Only the leaves are harvested in microgreens. Hence the root system must remain absolutely healthy.

Alternatively, if the coffee ground is less, the damage will not be that harsh. It can prevent microgreens from getting the necessary minerals and other nutrients. Thus, you must always ensure the ratio is perfect.

2. While Sprinkling The Grounds

If you want to sprinkle coffee grounds, ensure that you dig a little and put them inside. Do not just sprinkle them on the top of the soil. It is not good for your microgreens if you do this.

The coffee grounds will form a clump together immediately after you water them. This will create a barrier and will not allow the water to enter the soil. This, in turn, will stunt the growth of your microgreens.

3. Be An Active Participant

You need to participate actively in growing your own microgreens. You can do so by knowing where the coffee beans are sourced from. Also, how they remove the caffeine.

This will help you pick the best coffee grounds available. You will also have to check up on your microgreens now and then. This will be just to make sure if they are healthy.

You can also spot any diseases or bug infections on the microgreens by checking on them often. This will ensure they are growing well until it is time to for harvesting microgreens.


In this article, we have tried to answer as many frequently asked questions as possible. If you any doubts, hopefully, the following answers can help.

1. Can You Use Coffee Ground As Fertilizer?

Yes, you can use coffee grounds as fertilizer. They are known as a slow-release type of fertilizers. They contain an adequate amount of macro and micronutrients. It contains minerals like potassium, phosphorus, and magnesium.

You can add them to your compost or sprinkle them on your pot as ready-to-use fertilizers. They do excellent work in nourishing your microgreens with all the essential nutrients.

Also, they can attract worms that can help in fertilizing the soil better. These worms can also help in fixing the nitrogen content in the soil. Hence coffee grounds indirectly help in fixing nitrogen as well.

2. What Are The Health Benefits Of Microgreens Grown In Coffee Grounds?

Microgreens grown in coffee grounds do not have any special benefits from growing microgreens in another medium. However, all the benefits can be enhanced since coffee grounds improve the growth and health of the greens.

Some of these benefits are they reduce the risk of heart disease by decreasing the LDL cholesterol level.

It is also rich in antioxidants which are linked to a lower rate of diabetes. It can also decrease the chance of Alzheimer’s. Microgreens can also reduce the risk of obesity and helps you in leading a healthy lifestyle.

3. Can Coffee Grounds Be Used As Mulch?

Mulching is applying a layer of material over the surface of the soil to improve its fertility. It can be beneficial, yet, it is difficult to make. However, coffee grounds can be a solution for that.

The caffeine in the mulch mixed with coffee grounds can suppress the growth of unwanted plants. This will decrease the competition for your microgreens for nutrients, space, and sunlight.

However, some greens are more sensitive to caffeine than others. Hence, it is vital to avoid adding plenty of coffee grounds before understanding the individual requirements.

It is also crucial to ensure that coffee grounds are used to make mulch alongside plenty of other compost materials. This is because of the ability of coffee grounds to prevent the flow of water to the roots.

4. Can Coffee Grounds Cause Allergic Reactions In Pets?

Coffee grounds can be used to have negative effects on your pets. This is especially true if you have cats or dogs.

Does your pet always insist on smelling everything? Then it becomes necessary to avoid laying the coffee grounds anywhere in their reach. However, only a large amount of coffee grounds can cause poisoning.

Caffeine can be very dangerous for cats, dogs, and most other common pets. This is because pets are more sensitive to caffeine than human beings. It is crucial to keep your pet away from the coffee grounds while growing your microgreens.

5. Can I Replace Compost Pile With Old Coffee Grounds?

Coffee grounds can be an effective and efficient addition to a compost collection. They can boost the growth of microgreens with their rich level of nitrogen and minerals. They also provide a higher level of acidity that re good for some microgreens.

You can add them to your compost heap, wait until it you can mulch and bottle spray them. However, they can not be used as the sole fertilizer.

It is because of two main reasons. One is the acidity level and its harmful effects on the root.

The second one is that the coffee grounds can stick together and form a layer in the soil. This layer will prevent the water from reaching the root of your microgreens.

Hence, coffee grounds can be a valuable addition and not a replacement for a compost pile.

Let Us Wrap Up

It is apparent that using coffee grounds can give your microgreens an excellent environment to thrive in. If you do it properly, you need to understand the use of coffee grounds.

Hopefully, this article helped you understand the best conditions to grow microgreens while using coffee grounds.

Also, remember that with a little patience and a lot of care, you can grow your microgreens and enjoy the harvest anytime.