How to Use Ground Coffee on Your Plants

Ground coffee is used to prepare beverages, sweets, savory dishes and also to care for plants.
How to Use Ground Coffee on Your Plants

Last update: 10 March, 2023

Some people are unaware of the use of ground coffee in gardening. However, coffee is being more and more commonly used in gardening because it’s a natural and sustainable component.

Ground beans are suitable for soil conditioning, feeding vegetation, and even combating pests, for example. How to use it is determined by the gardener’s objective. We’ll talk about all the possible advantages and uses in this article.

The benefits of ground coffee for plants

Little has been said about the benefits that coffee provides in areas other than the culinary. It’s known to be a diuretic thanks to its chlorogenic acids and potassium salts; it also stands out in personal care, through its inclusion in shampoos, serums, creams, and other beauty products. When deodorizing the house, coffee also is a star due to its capacity to absorb odors.

To all these uses add the incorporation of the ground substance in the garden plots. The powder acts as organic matter for the soil and helps plants to thrive. It also contains nitrogen, phosphorus, and magnesium, micronutrients that can be used in acidic soils.

Although we still need further research to support the effectiveness of coffee on plants, it’s believed that it repels pests and cures fungi in ornamental species and in cucumber, spinach, and tomato crops, for example.

However, the warning of an article published by Servicultura Urbana and Ecologización Urbana is pertinent, highlighting the counterproductive effects of this substance on specific horticultural plants that have had a poor response to fertilization with coffee grounds. Some of them are below:

Planta de rábano.
The radish plant may not benefit from coffee, so be careful with this species as well as several others that are listed above.

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How to use ground coffee on your plants

Ground coffee is useful as a fertilizer, especially when combined with dried leaves and peels of vegetables, fruits, or eggs. Simply mix the ingredients and add them to the pot or directly into the soil.

If you have doubts about its relevance in certain plants, consult a specialist in a nursery if the species in question would tolerate the substance. However, almost any vegetable is compatible with coffee; hence its functionality in the following aspects stands out.

Pest and weed repellent

Snails and slugs avoid coffee, so they’re less likely to approach your plants. Likewise, the properties of caffeine prevent the growth of unwanted weeds.

Keep the soil fresh and with a barrier created with ground coffee in areas most prone to weed growth.

Coffee fertilizer

Although a bit costly, freshly ground coffee is an excellent fertilizer. The method consists of spreading a thin layer of the grind and letting it do its work.

However, it’s not a good idea to fertilize the species that are just germinating or for newly planted areas with coffee, since it increases the allelopathic process, and its caffeine can damage the plant.

Another way to fertilize with ground coffee is to mix 2 cups with 5 gallons of water, let it sit overnight, and spray the plants the next day.

Soil pH regulation

Science UNEMI evaluated in an experiment the chemical and physical quality of a compost prepared with coffee parchment. The mixture obtained the highest range of aeration porosity and total porosity compared to other composts whose bases were garden waste and bora. In terms of pH, electrical conductivity, and carbon-nitrogen ratio, the coffee remained within the adjusted ranges.

Worm food

Worms accept coffee as food. So says a text published by Ground to Ground, referring to the fact that this organic matter in the upper layer of a humid soil “calls” the worms to eat other remains, until they reach where the coffee is found. This form of vermicomposting is very beneficial for plants.

Lombrices que usan el café molido para crecer en jardinería.
If you practice vermicomposting, you can also add ground coffee to your formulas.


The University of Arizona points out in a publication that the fine texture of coffee compacts with the soil and is ideal for forming a mulch, favorable against humidity and air movement. The institution’s recommendation is that the layer is half an inch thick and reinforced with another layer of wood chips no thicker than 4 inches.

An acceptable mulching technique is to spread the ground coffee and then rake the soil to unite all the components so that the soil is level. Thus, the soil receives water smoothly and the caffeine covers the entire space without concentrating in any one spot.

It promotes rooting

Optimal concentrations of caffeine would hasten root growth and its quantity in rooted micro-scions. This is pointed out by BIO Web de Congresos, advising to discourage density above 0.1 %, as it has a negative effect on plant tissues, slowing down root formation, delaying shoot development and leading to tissue necrosis.

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If you have pets, be careful with ground coffee for plants

Ground coffee is a suitable alternative to treat certain species, considering its natural qualities. However, it’s advisable that you know how to properly work your garden with this product, because if you have pets, it could affect them.

In fact, the Affinty Foundation alleges that high levels of caffeine can intoxicate any dogs or cats that ingest the treated soil. According to GrowVeg, it’s also difficult to estimate the size of a dose that would cause poisoning in animals, because the amount of coffee grounds varies.

Given how curious pets can be, experts suggest burying as much of the coffee as possible and camouflaging and blending it well with the rest of the compost.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.