Do Cucumbers Like Coffee Grounds? (Here is The Answer)

One of the main questions when considering using coffee grounds in growing cucumbers is whether these plants really benefit from this additive or if it is just clickbait. Let’s look at whether or not cucumbers like coffee grounds are based on scientific research and explore the potential benefits and drawbacks.

Do Cucumbers like coffee grounds?

Cucumbers can benefit from the use of coffee grounds as a soil amendment. Coffee grounds are rich in essential nutrients like nitrogen, phosphorus, and potassium, which can promote healthy plant growth. Additionally, coffee grounds can improve soil structure and attract beneficial microorganisms like earthworms, which can further benefit cucumber plants. However, it’s important to use coffee grounds in moderation and monitor soil acidity levels, as too much acidity can harm your cucumber plants.

Reasons why coffee grounds are a good choice for cucumber plants

There are several reasons why coffee grounds are a good choice for cucumber plants. Cucumbers can benefit from soil rich in nutrients and organic matter, and coffee grounds are an excellent source of nutrients such as nitrogen, phosphorus, and potassium, essential for healthy plant growth.

Cucumbers exhibit a well-developed root system and are efficient plants at absorbing nutrients from the soil. Adding coffee grounds to the soil provides extra nutrients to the plants, promoting vigorous growth and increasing crop yields.

Coffee grounds can improve soil structure and increase water-holding capacity. This is very good for cucumbers, which have a high water demand.

In addition to these benefits, concerning the addition of organic matter, coffee grounds also contribute to a healthy microbial ecosystem. The beneficial microorganisms found in coffee grounds help break down organic waste in the soil, further improving soil fertility.

Scientific evidence on the use of coffee grounds in cucumbers

The best way to determine whether cucumbers benefit from coffee grounds is through the available scientific evidence. Several studies have shown that coffee grounds provide valuable nutrients to the soil, such as nitrogen, phosphorus, micronutrients, and other beneficial compounds for plant growth.

These nutrients are essential for plant development, promoting vegetative growth and improving disease resistance.

One issue to note is the response of cucumbers to coffee grounds is not constant and varies depending on many factors like the quality of coffee grounds used, the soil, the environment, and the growing conditions.

Benefits of using coffee grounds on cucumbers

Proper use of coffee grounds can bring benefits to the cultivation of cucumbers. Among the possible benefits are:

  • Increased soil fertility: Coffee grounds are rich in several essential nutrients. These nutrients help to strengthen the root system and provide the necessary elements for the synthesis of proteins and the development of the leaves and fruits of cucumbers.
  • Improved soil structure: Coffee grounds can also improve soil structure, increasing water holding capacity and improving drainage.
  • Pest-repellent action: Some studies have indicated that coffee grounds may have repellent properties against certain common cucumber pests, such as slugs and snails. This can help protect the plants from damage caused by these unwanted insects.

Disadvantages and considerations of using coffee grounds on cucumbers

While coffee grounds can have benefits, there are also some disadvantages and considerations to keep in mind:

  • Soil acidity: Coffee grounds are naturally acidic, affecting soil pH. Therefore, it’s essential to monitor soil pH and avoid overuse of coffee grounds, as this can lead to increased acidity, hindering healthy plant growth.
  • Excess of nutrients: Coffee grounds are rich in nutrients, but their excessive use can lead to an accumulation of nutrients in the soil, causing imbalances and absorption problems for plants. Use coffee grounds sparingly and in combination with other organic fertilizers to avoid overeating.
  • Quality of the coffee grounds: The quality of the coffee grounds used is a crucial factor to be considered. It is preferable to use organic coffee grounds, free of chemicals and undesirable additives. Furthermore, coffee grounds must be well-composted before being added to the soil to avoid harmful substances.

Signs That Your Cucumber Plant Likes Coffee Grounds

Here are some signs that your cucumber plant may be responding positively to the application of coffee grounds:

  1. Healthy growth: Cucumber plants that are thriving and showing healthy growth, including lush green foliage, strong stems, and vigorous development, can indicate that they are benefiting from the coffee grounds. Look for overall improvement in plant vitality.
  2. Increased fruit production: If your cucumber plant starts producing more flowers and setting a higher number of fruits, it could be a positive response to the coffee grounds. Coffee grounds’ nutrient content, particularly nitrogen, can promote flowering and fruiting in plants.
  3. Dark green leaves: Coffee grounds are a source of nitrogen, which plays a crucial role in chlorophyll production. If your cucumber plant’s leaves are a vibrant, dark green color, it can indicate that they are receiving an adequate supply of nitrogen from the coffee grounds.
  4. Improved soil structure: Coffee grounds contribute to the organic matter content in the soil, which helps improve soil structure and water retention. If you notice that the soil around your cucumber plant appears looser, crumbly, and well-draining, it suggests that the coffee grounds are positively influencing soil quality.
  5. Thriving beneficial organisms: Coffee grounds can promote the growth of beneficial soil organisms like earthworms and beneficial bacteria. If you observe an increase in the activity of these organisms around your cucumber plants, it indicates a healthy soil ecosystem, which is encouraged by the presence of coffee grounds.

How to use coffee grounds on cucumbers

Knowing how to use coffee grounds effectively is essential to achieving best practices in growing cucumbers. Following are some tips on how to incorporate coffee grounds into the soil and how often to apply it for the best results.

Composting coffee grounds

The best way to achieve maximum efficiency from coffee grounds, as well as to avoid problems, is through composting. Composting coffee grounds allows them to completely break down into nutrient-rich compost readily assimilated by plants.

To compost coffee grounds, mix them with other organic materials such as food scraps, dried leaves, and shredded twigs. This mixture will help balance the ratio of carbon and nitrogen, speeding up the decomposition process.

Ensure to turn the compost pile regularly to promote aeration and proper decomposition. In a few weeks to months, the coffee grounds will be completely decomposed and ready to be used as fertilizer.

Incorporation of coffee grounds into the soil

After composting, the coffee grounds can be incorporated directly into the substrate where the cucumbers will be grown.

Follow these steps for effective embedding:

  1. Prepare the soil: Before adding the coffee grounds, make sure the planting site is in good condition. Remove weeds and aerate the soil with a garden fork or hoe.
  2. Spread the coffee grounds: Distribute the coffee grounds evenly over the area where the cucumbers will be planted. Avoid placing large mounds of coffee grounds in one location, as this can lead to nutrient buildup.
  3. Soil incorporation: Using a rake or hoe to incorporate the coffee grounds into the soil. Gently mix it in, ensuring it’s well integrated into the soil. This will allow the nutrients in the coffee grounds to be absorbed by the plant roots equally and efficiently.

How Often to Apply Coffee Grounds to Cucumber Plants

The frequency of coffee grounds application will depend on soil conditions and plant needs. In general, it’s recommended to apply coffee grounds every two to three weeks during the cucumber growing season.

However, you must monitor the soil and plants to avoid excess nutrients. If there are signs of nutrient buildup or soil imbalances, reduce the frequency of coffee grounds application.

Remember that coffee grounds should not be used as the only fertilizer for cucumbers. Sludge should only be used as a supplement to other organic fertilizers such as compost, manure, or balanced compost to provide a variety of nutrients needed for healthy plant growth.

By following these tips, you will use coffee grounds effectively in growing cucumbers, improving soil quality and providing valuable nutrients for plant growth. Remember to adjust the dosage and frequency of application according to the specific needs of your garden and plants.

Other ways to use coffee grounds in growing cucumbers

In addition to directly incorporating the sludge into the soil, there are other creative ways to take advantage of its benefits in growing cucumbers.

Let’s look at some options:

  • Coffee grounds tea: A popular way to make use of coffee grounds is by brewing tea for watering your cucumber plants. To make tea, place coffee grounds in a container and add hot water. Let the mixture steep for a few hours, then dilute the tea with water before watering the root crops. This coffee ground tea is rich in nutrients and can be applied weekly to support plant growth.
  • Ground cover: Another interesting way to use coffee grounds is as a ground cover around cucumber plants. Apply a thin layer of coffee grounds over the soil, keeping an adequate distance from the plant stems to prevent moisture build-up. This ground cover helps control weed growth, keeps the soil moist, and adds nutrients gradually as it decomposes.
  • Vermicomposting: Coffee grounds can also be used as food for worms in a vermicomposting system. By adding coffee grounds to compost or vermicomposts, earthworms feed on it, transforming it into high-quality compost. This compound can be added to cucumber soil, providing a continuous source of nutrients over time.
  • Liquid Fertilizer: You can create a liquid fertilizer enriched with coffee grounds to nourish your cucumber plants. To do this, place the coffee grounds in a container of water and let it infuse for a few days until it ferments. Then dilute the mixture with water before watering the plants. This liquid fertilizer is rich in soluble nutrients that can be absorbed quickly by plant roots, promoting healthy growth. This fertilizer can also be used foliarly, when well diluted (20:1).

It’s essential to remember that while coffee grounds are beneficial for cucumbers, it’s essential to use them in moderation.

Excessive coffee grounds can lead to the accumulation of nutrients in the soil, which can cause fertility problems. Therefore, always monitor the soil and plants to ensure proper balance.


By exploring different ways to use coffee grounds to grow cucumbers, you’ll be making the most of this valuable resource, reducing waste, and promoting a more sustainable garden.

Experiment with these techniques and adapt them to your specific needs, taking into account soil conditions, the local climate, and the characteristics of your plants.

Remember that gardening is a continuous learning practice, and each garden has its particularities.

Be open to experimenting, observing, and adjusting your practices to your plants’ needs. Over time, you will develop in-depth knowledge of growing cucumbers and enjoy healthy and tasty harvests.

Andreea Tapu

Andreea TAPU is a passionate gardener with over 5 years of experience in cultivating a wide variety of plants and flowers in her garden. As the author and creator of, she is dedicated to sharing her knowledge and expertise with others, providing practical tips and advice to help gardeners of all levels achieve success and enjoyment in their gardening pursuits.