Are Coffee Grounds Good for Houseplants?

Are coffee grounds good for houseplants?

Are you thinking about using coffee grounds for your houseplants? If so, there are a few things you’ll want to know before collecting those grounds. If used correctly, coffee grounds can help your houseplants flourish. Read more about the ways that you can use coffee grounds to grow better quality houseplants. 

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Why Use Coffee Grounds?

Coffee grounds can be an excellent asset to your gardening experience. Because coffee grounds are organic material, they add aeration and improve drainage in the soil. If unwashed, they will make your soil more acidic, which is great for plants like lilies. If you rinse your coffee grounds, they will have a neutral pH, making them appropriate for almost any type of plant.

Coffee grounds are also a green choice for fertilizing and mulching. They are zero-waste, low-cost, and easy for almost anyone to obtain. Save money and save the earth by recycling your coffee grounds as mulch or fertilizer.

How to Use Coffee Grounds in Houseplants

What are the ways you can use coffee grounds in your houseplants? Here are a few methods for getting the most from your coffee grounds.

Coffee Grounds as Mulch for Houseplants

Mulch can be a great addition to houseplants, for several reasons. Mulch can improve the appearance of the soil, improve drainage, and help retain moisture. It can also prop up stems that have started to droop.

To use coffee grounds for mulch, first rinse the coffee grounds thoroughly to remove the acidic properties. Let the grounds dry, and then spread lightly over the top of your soil.

Coffee grounds can also be used on a larger scale to mulch outdoor flower beds or gardens — just follow the same process!

Coffee Grounds as Fertilizer for Houseplants

In addition to mulch, you can use coffee grounds as fertilizer for your houseplants. The phosphorus, potassium, nitrogen, and other types of micronutrients that are in coffee grounds can be very beneficial for your houseplants. Plus, coffee grounds are cheap, easy, and natural!

The first step to using coffee grounds as fertilizer for houseplants is rinsing. You’ll want to rinse your coffee grounds well to neutralize the pH, unless you are adding coffee grounds to acid-loving plants, like lillies or ferns. When in doubt, rinse before adding.

After rising, simply add the coffee grounds into the soil around your houseplant. Start with a small amount, and adjust based on the results you see. It will take some trial and error to find the right blend of soil and coffee grounds, so start small and gradually work your way up.

Adding Coffee Grounds to Compost

You can put the coffee grounds in the compost, as well. Coffee grounds are green compost material, so you will want to make sure you are balancing the coffee grounds out with some brown compost material (like woody prunings, old newspapers, or dried leaves). By mixing these things properly, together they can all work together to fertilize your plants. 

If you do vermicomposting with earth worms, coffee grounds also make an excellent worm food!

Coffee Grounds as Natural Pesticide for Houseplants

Coffee grounds can also be used as a natural pesticide, because they help repel slugs and snails. While this might not be necessary for indoor houseplants, if your plants spend any time outdoors in the summer, coffee grounds are an added layer of protection.

Coffee grounds can also be an excellent cat repellant. If your cats love to dig in your plants, or use them as a litter box, a light sprinkle of coffee grounds can keep them away.

Possible Issues with Coffee Grounds and Houseplants

Coffee grounds can be beneficial to the soil of your houseplants. However, there are some things that you have to be careful with if you’re going to add coffee grounds to your houseplant soil.

Adding too much caffeine

The main reason an issue could occur is that there is caffeine in coffee grounds. Adding too much caffeine to the soil of your houseplants could suppress their growth. This is why it’s extremely important to only add a small amount of coffee grounds to the soil of your plants at a time. If you don’t see a change, add a small bit more, but always err on the side of caution.

Blocking moisture

In addition, coffee grounds have extremely fine particles. These often lock together, causing them to act as a barrier for water. This means the water can’t flow through the soil or get to the roots of your plants.

If you aren’t cautious on how much of the coffee grounds you are using, you could dry out your plants. Again, using small amounts of coffee grounds is key.

If you choose to mix your coffee grounds with another organic option such as leafmold, you can reduce the chances of the coffee grounds harming your plants. You should also spread the coffee grounds across the soil of each plant, to prevent the clumping from happening.

Caution: Dogs and Coffee Grounds 

If you are going to start using coffee grounds in your houseplants, you should take note of the cautions of doing so. It is important to know that, in larger doses, coffee grounds can be dangerous to pets (dogs especially). It is difficult to know exactly what dose would be too much. However, it is best if you can have your dogs and other pets avoid the coffee grounds altogether, so they don’t get poisoned from the caffeine.

Here are some more great tips for keeping dogs safe around houseplants.


If you want to grow beautiful plants, but you don’t want to spend a fortune on fertilizers and supplements, give coffee grounds a try! You’ll be amazed at just how much this cheap natural fertilizer will help your plants thrive.

Kate Inskeep

Kate Inskeep is a mom of three from Illinois who loves growing things. She fell in love with houseplants after a friend gifted her some succulents. Before long, her windowsills were full of plants, and she was hooked.

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