Watering your plants with coffee?

Do you drink coffee every morning and wonder if the last of your cup should end up down the sink? Is it a good idea to pour a few drops on your plant?

We are passionate about plants and have tested this for you.

Along with tea and milk, coffee is one of the ingredients in our kitchens that can be recycled for gardening. Coffee is an excellent natural fertilizer when diluted in your watering can. In small doses, it contributes to plant growth by providing them with minerals. Coffee grounds are also a natural way to keep insects away from your soil.

In this article you will discover:

• The benefits of coffee for plants.
• Classic mistakes that are harmful to your plants.
• Should I use liquid coffee or coffee grounds?
• Coffee as a natural pesticide.

You'll never throw away a single drop of coffee again after reading this article. You'll know exactly how and where to recycle the leftover coffee grounds.

Let’s discover the secrets of coffee for plants now!

1. Is coffee good for plants?

Coffee infusion contains a large amount of water, which plants need greatly. Furthermore, coffee also contains several hundred components that are very good for plants . Among them are potassium and magnesium , which are essential for the healthy growth of hardwood trees. On the other hand, other elements such as caffeine can be toxic to plants in excessive quantities . In short, the majority of components in liquid coffee pose no danger to garden crops.

By recycling the end of your cups, all of these ingredients will be quite diluted. These potentially harmful substances will quickly decompose once they come into contact with the microbes in your soil.

Another factor to consider when determining whether coffee is good for your plant is the acidity of its soil . Coffee has a pH of around 5, while plants prefer less acidic growing media (pH between 6 and 7). However, rainwater has an acidity level equivalent to that of liquid coffee, so plants are already used to dealing with acidic water from the sky.

From a theoretical perspective, watering your crops with liquid coffee for several months in a row could potentially make the soil more acidic . This could be detrimental to some crops, but beneficial for acid-loving plants such as African violets, begonias, and phalaenopsis. However, this is unlikely to happen, as watering can hardly change the acidity level of a growing medium.

Including coffee in your watering is a cost-effective tip that will provide your plant with minerals . In reasonable quantities, it is unlikely to harm your favorite green plants.

2. How to water your plants with liquid coffee?

Now let's look at how to pair coffee with your watering habits. There are some mistakes to avoid, some of which can be counterproductive.

B) Dilute the coffee in the water from your watering can

The best way to water your plant with coffee is to include it in your watering routine . To do this, dilute the last of your cold brew coffee in the water already in your watering can . Doing this will dilute the components of the coffee in a larger quantity of water. This technique will allow your plant to better absorb the minerals . The advantage of a good watering can is that it also allows you to water the roots of the plants more precisely.

The amount of water should therefore far exceed that of the brown powder. To do this, prepare your drink as usual and add at least two glasses of water, depending on whether it is strong or not. Let the resulting mixture sit in a watering can or sprayer before applying it to your plants.

Of course, not all plants require the same amount of water to thrive. However, we can safely recommend adding a little coffee to your watering routine once a week.

A) Classic mistakes to avoid?

There are a few precautions to take when using this method. First, you must wait for the coffee to cool before watering your plant . The roots are not at all prepared for hot water and may react badly.

We also advise you to avoid flavored or overly sweet coffee blends . They contain a higher concentration of compounds that can be harmful to living organisms in the soil and cause unpleasant odors and even fungus.

A little milk or cream in your cup is not a problem, however. As we saw in our article on watering with milk , it is also a beneficial natural fertilizer in small doses.

3. Coffee grounds: what are they used for?

The kitchen is full of many hidden treasures that end up in the trash at the end of the day. Coffee grounds are one of them, and they have many uses, particularly in gardening.

A) Reuse coffee grounds as fertilizer

This coffee residue obtained after infusion contains a significant amount of nitrogen (around 3%). However, this is not directly assimilated by plants and you must compost the coffee grounds so that the gaseous compound is gradually released. Coffee residue also contains elements such as magnesium , potassium and phosphorus . These components are directly assimilated by plants and can reduce the risk of deficiency .

Coffee grounds also contain organic matter. However, they don't have enough nitrogen to allow for carbon decomposition. When you add them directly to the soil around your crops, the nitrogen will be drawn from the soil to begin the mineralization process. As a result, plants will no longer be able to assimilate it and will experience a deficiency. Therefore, be sure to use this fertilizer sparingly to avoid nitrogen deficiency in your plants.

B) Use coffee grounds as a pest repellent

Leftover coffee grounds can serve many purposes. In addition to being a relatively effective fertilizer, coffee grounds can also act as a pest repellent that often disrupts the growth of your crops. In fact, caffeine can effectively keep insects away from your garden. It even has biocidal properties that can render arthropods in the vegetable garden harmless and keep earthworms away from your plants .

This ingredient is also a very powerful repellent against ants and aphid infestations . However, there is no point in putting coffee grounds at the base of your crops that are already prone to aphid attacks. The latter will not descend from the leaves to the soil, so the caffeine will not be able to reach them.

Slugs and snails are not particularly sensitive to the repellent properties of coffee grounds. However, they can be physically bothered when used as a barrier around sensitive plants in hot weather. Coffee grounds are ineffective against mollusks in humid conditions. Be careful not to overuse this element, as it can have a negative impact on garden wildlife, especially in the compost heap .

C) Make potting soil with coffee grounds

The nitrogen content of coffee grounds makes them an excellent ingredient for making compost. In addition, their significant potassium and phosphorus content make them a true ally for crops, as they promote their growth. Not only does it improve the quality of your garden soil, it also provides nutrients and energy.

The presence of a large amount of nutrients in coffee grounds allows it to stimulate plant flowering and increase the organic matter content of the soil.

4. Which plants should be watered with coffee?

Due to coffee's slightly high acidity, you can't use it to water all plants, especially those that are sensitive to acidity. However, the liquid with a pH between 5 and 6 could greatly benefit plants such as:

• ferns;
• amaryllis;
• the hyacinth;
• roses;
• begonias;
• African violets;
• aloe;
• hydrangea;
• azaleas;
• and gardenias.

Grab your Watering Can and Take Action!

As we've seen, watering with coffee grounds is a fun way to recycle coffee grounds that have cooled down too much. In addition to being an economical fertilizer, it's completely natural and contains no chemicals.

Now that you've learned this new eco-friendly technique, you can fertilize your plants with your next cup.

To do this, grab your watering can and dilute the last of your drink into the water you're watering. Combined with the precise and controlled watering of a watering can, your watering will become efficient and professional.

Discover our indoor watering cans now by clicking on the image below: