Are Coffee Grounds Good for Houseplants? Find Out Below

What Plants Like Coffee Grounds?

Many people ask, “Are coffee grounds good for houseplants?” and, “What plants like coffee grounds?” Roses, azaleas, lilies, and hollies are acid-loving plants. They flourish best in the acidic nature of coffee grounds. Acid-loving plants like coffee grounds because they lower the soil’s pH level, making it more acidic.

However, coffee grounds may not work for all plants. Some are coffee-ground sensitive and may develop brown leaf tips if they come into contact with them. 

Coffee beans spilling from a bag

Are Coffee Grounds Good for Houseplants?

Yes, coffee grounds can benefit indoor plants because of their high nitrogen content, micronutrients, and water retention. Composting is the best method to use coffee grounds on houseplants! You can also use coffee grounds in potted plants. 

Additionally, you may also make basic plant fertilizer out of leftover liquid coffee. Remember that using coffee grinds will raise the soil’s moisture level. This is perfect for plants that prefer damp soil!

However, keep coffee grounds and potting soils away from plants that require dry soils, such as succulents and cacti. Additionally, you should avoid applying raw coffee grounds directly to your indoor plants because they can significantly boost soil moisture levels, thus harming your plant’s growth in various ways.

Do Coffee Grounds Help Plants?

Coffee grounds have various benefits that can positively impact plants. This organic matter contains abundant nutrients essential for plants to thrive, including nitrogen, potassium, and phosphorus. Coffee grounds can revive root growth and nourish plants when you use them as fertilizer.

Apart from nourishment, coffee grounds can also serve as a natural weed suppressor and foster the growth of good microorganisms in the soil. Also, caffeine in coffee grounds exhibits some herbicidal properties, which can inhibit the growth of certain weed species. 

Furthermore, the organic matter in coffee grounds can serve as a nutritious food source for soil microorganisms, consequently cultivating a robust soil ecosystem.

However, the excessive use of coffee grounds can elevate soil acidity, which can be unfavorable to plants that prefer alkaline soil. As with any fertilizer, it is imperative to undertake due diligence and comprehend the specific requirements of your plants before utilizing coffee grounds as a fertilizer.

How to Use Coffee Grounds as Fertilizer

To employ coffee grounds as a fertilizer, you must first gather them in a tin. You can accumulate the grounds from your morning cup of coffee or solicit your neighborhood coffee establishment for its expended grounds. Ensure that you gradually collect the coffee grounds to have sufficient for your plants.

After you collect enough coffee grounds, sprinkle them around the foundation of your plants. You can accomplish this by simply sifting the coffee grounds atop the soil or by integrating them into the soil with a garden trowel or cultivator.

It is critical to note that although coffee grounds may benefit most plants, you should not overuse them. It is generally advisable to use coffee grounds in moderation and combine them with other organic material forms, such as compost or mulch.

What Do Coffee Grounds Do for Plants?

Increases Soil Drainage

Used coffee grounds are a free organic substance, so adding a few cups of grounds now and then can be a smart method to increase soil quality. Increase the quantity of organic material in your soil to promote drainage. This helps to ensure that water does not sit around plant roots and cause rot.

Every gardener understands that good drainage is vital for healthy plants, so there’s no excuse not to repurpose your coffee grounds when they’d otherwise end up in the trash. When adding coffee grounds to promote drainage, one guideline to remember is thoroughly mixing them with the soil. 

Coffee grounds contain very minute particles that can become compacted if not combined adequately with other materials, creating barriers comparable to clay soil. 

It Aids in Soil Aeration

Adding coffee grinds to the soil will assist in aerating it in the same way it would enhance drainage. Enriching the soil with organic matter improves aeration, allowing roots to absorb moisture and nutrients better and improving overall plant health.

Enhances Soil Water Retention

Coffee grounds promote water retention because they are organic matter that improves the ability to retain water. This will benefit plants that prefer moist soil, as the soil will stay moist for longer after rain or watering. Soil that retains water well requires less frequent watering, which can lower water bills and save energy.

Adds Nitrogen to Compost

Even though it is brown, you can compost coffee grinds as green trash. Coffee grounds contain considerable nitrogen, which will decompose and produce a compost rich in critical elements. Because nitrogen promotes lush green growth, employing a compost containing coffee grinds among your plants will improve foliage health.

Can Deter Slugs and Snails from Plants

Many people believe that used coffee grounds keep slugs and snails away. These nasty bugs are a major nuisance for gardeners since they feed on foliage, which can be unsightly and, in some circumstances, cause plant decline and deterioration. 

The fragrance and taste of the coffee grounds help to prevent these pests, and the gritty texture can act as a physical barrier that slugs and snails do not want to cross.

It Can Act as a Cat Repellant

You are not alone if you have a problem with cats spraying or pooping in your garden. Cats frequently use gardens as litter trays because they prefer defecating on soil, mulch, and gravel. This is an unpleasant problem that many gardeners face, and it is highly distressing to discover that the garden you have spent time tending has become overrun with cat feces. 

If you have children, this is a major issue because cat droppings and urine include substances that can be extremely dangerous if touched or swallowed by people. To combat a cat problem, scatter coffee grounds about your plants or mix it into the top layer of soil. 

But if you have a severe cat problem, you may need to use it with other preventative measures. Make sure not to build a carpet of coffee grounds, as this can prevent the soil from receiving moisture.

Encourages a Good Worm Population

Coffee grounds are a common food source for worms, so adding them to your soil or compost will help expand the worm population. A healthy worm population in your garden is essential for plant root health and compost breakdown. Worms enjoy eating coffee grounds, so adding this green material to your compost regularly will keep them happy and functioning.

Can Act as a Mulch

You can use coffee grounds with other organic resources, for instance,  shredded leaves as mulch. When laid over the top of the soil surrounding plants, this can assist in keeping moisture in the soil from evaporating. It can also help the soil retain heat in the winter and maintain cool in the summer.

Mulching your soil can also help to keep weeds at bay. Weed seeds will be unable to enter the soil as easily because the mulch acts as a physical barrier, and it also inhibits light from entering the soil, preventing many forms of weeds from sprouting. 

If you wish to use coffee grounds as mulch, mix them with another organic material because the little particles can become compacted and prevent water from getting through to the soil if used alone.

Works as a Slow Release Fertilizer

Adding coffee grounds to your soil will introduce slow-release nutrients, making it an efficient fertilizer. Used coffee grounds have a high nitrogen content, low phosphorus and potassium levels, and some other micronutrients. 

These are all vital nutrients for plant health; therefore, including them in your soil will be beneficial. They will not be instantly available to the plant’s roots and will be available gradually during the ground’s breakdown cycle, making them ideal as a gradual fertilizer.

Reduces Waste And Chemical Usage

Coffee grounds are a waste product that, if not reused, will wind up in the garbage can and, eventually, in a landfill. Recycling or reusing any item is an excellent approach to helping the world and the environment. Coffee grounds are an organic resource that, when recycled, can be an environmentally responsible option.

When you use coffee grounds instead of synthetic fertilizer, you reduce the number of chemicals that enter the ground and contribute to a more organic and natural landscape while safeguarding local waterways and the delicate balance of the ecosystem.

Coffee beans in coffee cups

Are Coffee Grounds Good for Vegetable Plants?

Coffee grounds supply vegetable plants with a wealth of nutrients and chemicals, including protein, nitrogen, fatty acids, and essential oils. 

Coffee grounds added to the compost bin break down and release these compounds, making the compost a healthy addition to the soil in your vegetable garden. When covered with a layer of mulch, coffee grinds make an excellent soil amendment.

The Benefits of Using Used Coffee Grounds as a Fertilizer

When used as a fertilizer for plants, used coffee grinds can offer several benefits, including the following:

  • Rich in nutrients: Used coffee grounds are an excellent source of various nutrients, including phosphorus, potassium, and nitrogen, all of which are necessary for the healthy growth of plants.
  • Increases the soil’s capacity to retain nutrients and water. The organic matter in used coffee grounds can help to increase the soil’s capacity to retain water and nutrients, improving the soil’s structure. Better aeration of the soil, which can stimulate the formation of roots, is another benefit of this practice.
  • Used coffee grounds have some herbicidal qualities: This can aid in restricting the growth of certain species of weeds. This property is responsible for the weed-suppressing effect.
  • Used coffee grounds contain microorganisms: These microorganisms can assist in building a healthy soil environment. This, in turn, can help increase plant growth and reduce the danger of diseases affecting plants.
  • Helps to reuse wastes: Using used coffee grounds as a fertilizer is an excellent approach to reuse waste that you would otherwise dump in a landfill. It is an alternative that is both sustainable and kind to the environment, and it can help you reduce carbon impact.

When are Coffee Grounds Not Ideal for Houseplants?

Attracts Pests & Diseases

Coffee grinds are popular because they bring beneficial bugs and microorganisms to the soil. Unfortunately, this also implies that they attract harmful bugs. Whether blended into the soil or used as mulch, coffee grounds attract various common pests to your houseplants.

They make a perfect home for soil-dwelling fungus gnats. Other houseplant pests attracted by wetness and humidity include thrips and mealybugs.

Coffee grounds’ moisture retention qualities are also known to promote disease, particularly fungal infections that thrive in the warm temperatures and high humidity that most houseplants appreciate.

If you incorporate coffee grinds into the soil, watch for insect or disease infestation signs. To avoid the spread of any problems, use an insecticidal spray, horticultural oil, or fungicide as soon as possible.

Compacts Around Soil 

When wet, coffee grounds retain a lot of moisture. When they dry out, though, they become compressed and repel moisture. This is why dry coffee grounds from a coffee machine can harden and become difficult to break down or rehydrate.

If you add coffee grounds to your soil and have a habit of drowning your houseplants, it will be tough to hydrate the soil thoroughly. Water will run down the edges of the container rather than into the soil because the coffee grounds repel water, leaving the roots entirely dry.

This is a major issue when utilizing grounds as mulch, which is a frequent recommendation. When the coffee grounds on top of the soil dry up, they repel water and prevent it from reaching the roots. You also cannot maintain the grounds continually damp, as this can cause root rot.

You should do watering with care when using coffee grounds. Those who frequently overwater their plants or neglect to water them may consider a different soil amendment or mulching material.

Can Limit Growth

The results of several research papers on using coffee grinds are disappointing. Unfortunately, contrary to popular belief, excessive volumes of coffee grinds applied as mulch or in the soil can impede plant growth—the caffeine levels in coffee cause this behavior. 

While some believe that the caffeine in used coffee grounds is low (to around 20% of the original amount), used coffee grounds still contain caffeine levels that are too high for houseplants to handle. Root development and germination are both hampered. Leaves may turn yellow and fall off the plant if caffeine levels are too high.

The trick to utilizing coffee grounds for houseplants is moderation. Don’t go overboard and supplement your soil with a half-and-half ratio of coffee grounds, as this will likely cause more harm than good. To protect your houseplants, use them sparingly and never as mulch.

Can Cause Root Rot

While coffee grounds might pose issues for gardeners prone to overwatering, they can also exacerbate situations of overwatering. One of the most prevalent reasons for houseplant death is overwatering. 

Excessive wetness in the soil makes the roots mushy, rendering them incapable of absorbing water and nutrients. If left untreated, this inhibits growth and might eventually kill the plant.

Because coffee grounds hold a lot of moisture, keeping them moist for lengthy periods might exacerbate overwatering issues. While moisture retention is normally beneficial, those who overdo it may suffer. Avoid scheduling watering and testing soil moisture every few days to reduce this risk. Most houseplants will require additional watering once the topsoil dries out.

You can also use a moisture meter to ensure you never under or over water again.

The verdict on the usage of coffee grinds in indoor gardens is still out. While there are certainly some advantages, there are also several concerns.

Soil pH and Coffee Grounds

When considering coffee-specific plant care procedures, it is critical to understand how they can alter soil pH. It’s time for a quick scientific lesson! The pH scale ranges from 0 to 14, with 7 being neutral.

Acids have a pH range of 0-6.9, while bases have a pH range of 7.1-14. So, high acidity equals low pH. Understanding the fundamentals of soil pH is critical for the health of your plants. Most plants prefer a lower pH than neutral because it improves nutrient absorption.  

There are, however, risks to going too low. When soil pH falls too low, the range of nutrient availability expands to dangerous levels. This can cause stunted growth in plants.

Coffee grounds not brewed are highly acidic, and you should never use them on your plants. Like raw coffee grounds, liquid coffee is highly acidic, and you should not spray on plants without first diluting it.

On the other hand, used or brewed coffee grinds have a far reduced danger of significantly decreasing soil pH. However, you should know that they are slightly acidic and may affect the soil of your plants.

Coffee grounds and beans


Plant owners use coffee grinds in their houseplant care routine for various reasons. They contain a lot of nitrogen and micronutrients. Coffee grounds are widespread in most homes, making them an easily accessible substance. 

Gardeners can take pride in the fact that they are taking something that might otherwise end up in the landfill and reusing it to improve their plants. Furthermore, coffee grounds are a very inexpensive choice of fertilizer.

When using coffee grounds on plants, remember, as with any plant care procedure, it is critical to completely grasp each plant species’ care requirement to best assist them in thriving!