Coffee Grounds As Fertilizer: Uses & Benefits

Coffee grounds are a popular home remedy for fertilizing orchids, roses, etc. We show why coffee is good for your plants and how to use it.

Many of us don't really get going without our morning coffee. But have you ever thought that you could also use the coffee grounds to give your plants an energy boost? We will show you what else is in your coffee grounds and how it can help us in the garden.

Every German drinks an average of 165 liters of coffee a year - there are plenty of coffee grounds. The coffee grounds are the substance that remains in the filter after the coffee has been made. There are a variety of uses for coffee grounds, but most just toss them in the trash and miss out on a lot. Coffee grounds can be used to control pests such as fungus gnats or as a compost additive.

Properties of coffee grounds

Coffee grounds have many different ingredients that we can use. In addition to nitrogen, phosphorus and potassium, it also contains tannic acids, antioxidants and traces of caffeine. Basically, an average of 2% nitrogen, 0.4% phosphorus and 0.8% potassium remain in the coffee filter.

Since the coffee grounds are slightly acidic (its pH is around 6.5), they are particularly suitable for plants that prefer acidic soil. These include, for example, citrus plants (citrus). More to fertilization of citrus crops such as lemon trees can be found here.

Benefits of coffee grounds as a fertilizer

Of course, one of the biggest advantages of using coffee grounds as a fertilizer is that it accumulates in every household and does not have to be bought separately. This saves you a trip to the hardware store and you can reuse a waste product in this way. Coffee grounds are also attractive to earthworms. This is a great advantage, because earthworms loosen the soil and give it a crumbly structure. They also help break down organic matter in the soil.

However, coffee grounds have a repellent effect on pests such as snails or ants. These little pests don't like the smell of coffee or the caffeine and will therefore avoid the areas that are fertilized with it.

So, the benefits of using coffee grounds as a fertilizer are as follows:

• Occurs in the household
• Is (in principle) free
• Slightly acidic pH
• Attracts earthworms
• Repels snails and ants

For which plants is coffee grounds suitable as fertilizer?

When using coffee grounds as fertilizer, it is particularly important to ensure that they do not become moldy. So dry the coffee grounds thoroughly. There is a risk of mold especially in fully automatic coffee machines where the coffee grounds are collected in a container for a long time. But no matter what kind of coffee maker you own, always dry the coffee grounds before using them as fertilizer to reduce the risk of mold. To do this, simply spread out the wet coffee grounds flat – for example on a baking tray – and let them dry there.

For use, you should not only sprinkle the dried coffee grounds over the soil, but rather work them into the soil. This allows it to be broken down better and release the nutrients where they are needed. However, you should not overdo it with coffee grounds fertilization.

Fertilize garden plants with coffee grounds

In the field you can fertilize up to four times a year with coffee grounds. Over-fertilization with coffee grounds is practically impossible. It is best to simply work the substance into the soil a little. You can also simply mix the dried coffee grounds with potting soil and plant your plants in this soil. All you have to do is mix the contents of a coffee filter (about 30 g of coffee grounds) with the potting soil in a 10-litre bag. That way the soil won't acidify too much. You can also simply put the coffee grounds on the compost and let them rot there. There it has a positive effect on composting and also provides nutrients. This method is extremely effective because the coffee grounds attract earthworms, which help with composting. This way you get an optimal one organic fertilizer.

When it comes to dosing, it is of course also an advantage if you do your own experiments and start with small amounts at the beginning. The needs of the plants and their sensitivity are often very different.

Fertilize houseplants with coffee grounds

For indoor plants, it is sufficient to fertilize once in winter and once in spring. One to two full teaspoons per plant are sufficient for this, which corresponds to about 4 to 8 g of coffee grounds per plant. Be careful, though, as this will lower the pH in the pot and some of our houseplants may take offense. Don't forget to repot your houseplants regularly afterwards and provide them with fresh substrate.

You can still mix the coffee grounds or leftover coffee with water and water your houseplants with it. For example, mix old coffee and irrigation water in a ratio of 1:1 and use it to water your plants. Make sure, however, not to water the leaves, but simply around the base of the plant. This allows you to water and fertilize in one step.

Coffee grounds as flower fertilizer

When you talk about flowers, you usually mean annual summer flowers. These bloom profusely and usually have a high nutrient requirement. Because coffee grounds contain only small amounts of nutrients, fertilizing the flowers with them is not harmful, but by no means sufficient. The large amount of organic material and the tannic acids contained also inhibit a rapid release of the nutrients contained. Our hungry summer flowers could even slip into malnutrition if they were given too much coffee grounds.

Nevertheless, the beauties can benefit from the coffee grounds: Together with a strong flower fertilizer - such as ours Plantura organic flower fertilizer – soil organisms convert the hard-to-digest coffee grounds. This can produce valuable humus. This improves the soil properties, which is very convenient for the often somewhat spoiled summer flowers. To do this, mix coffee grounds and flower fertilizer in a ratio of 3:1. A good alternative to this process is to compost the coffee grounds along with more nutrient-rich waste. You can then use the compost to fertilize your summer flowers.

Coffee grounds as a fertilizer for orchids

The beautiful ones orchids (Orchidaceae) also benefit from coffee grounds as fertilizer - but only when planted in orchid substrate. If your orchids are growing hydroponically, fertilizing with coffee grounds is unfortunately not an option. The coffee grounds are very easy to use on orchids: you spread the coffee grounds on the surface and then simply water the orchids. Another option is to mix some coffee grounds into the soil. However, be careful not to use too much coffee grounds, as orchids are extremely delicate houseplants. This is where you should try first and see what happens. Just add a small amount of coffee grounds to the orchids and keep an eye on the plant. If the plant eventually changes negatively, it is better not to use this fertilizer for your orchids. More about the right one Care of orchids find out here.

Coffee grounds as fertilizer for roses

roses (pink) please our eyes with their wonderful flowers. But the queen of flowers needs a lot of nutrients, after all she is one of the heavy consumers. To give your roses a boost of energy, you can sprinkle about half a cupful of coffee grounds around your roses and rub them lightly into the soil once a month. You can do this until the end of June, but after that roses should no longer be fertilized. You can safely use coffee grounds as an alternative or as a supplement to your usual one rose fertilization Use and then enjoy the great effect. However, the coffee grounds usually contain too few nutrients to fertilize your roses exclusively with them.

Coffee grounds as fertilizer for hydrangeas

hydrangeas (Hydrangea) should ideally be bushy and bloom profusely. But this only works if they are properly supplied with nutrients. After all, they place high demands on the soil. Coffee grounds are therefore ideal as supplementary fertilization for hydrangeas, because they prefer acidic soil - coffee grounds are slightly acidic.

It also contains many minerals and optimally supports the hydrangeas in their growth. However, coffee grounds alone are not enough to fertilize hydrangeas, because the nutrient content is ultimately too low for that. However, it is an ideal supplement to your conventional hydrangea fertilization. Do not just scatter the coffee grounds around the hydrangeas on the ground, but work them into the soil so that they can develop their full effect. A thick layer of coffee grounds can quickly form a water-impermeable layer on the surface, which of course is undesirable. If you want more about the Fertilizing and caring for hydrangeas If you want to know more, you can find more information in our special article.

Coffee grounds as fertilizer for tomatoes

Also tomatoes (Solanum lycopersicum) can be fertilized with coffee grounds. However, they are highly consuming vegetables and therefore require many nutrients. Coffee grounds are certainly an effective fertilizer for tomatoes, but unfortunately not enough. You should therefore only use the coffee grounds in addition to an optimum tomato fertilizer use. Our Plantura, for example, is suitable for this Organic Tomato Fertilizer Perfect. This supplies your tomato plants with the necessary nutrients and consists of purely vegetable components. For potted tomatoes, however, is the liquid one Plantura Organic Tomato & Vegetable Fertilizer better suited as incorporating a granular fertilizer would stress the plants.

Coffee grounds as an organic fertilizer supplement

Coffee grounds contain important nutrients and offer an optimal fertilizer supplement to supply your plants with nutrients. However, the nutrient content in coffee grounds is too low to fertilize with coffee grounds alone. Another possibility is the use of coffee grounds as a supplement to another fertilizer - such as our Plantura organic fertilizer. This gives you an optimal, well-rounded supply of nutrients in your garden.

More and more hobby gardeners rely on vegan products in their garden - including fertilizers. Here you can find out all about the advantages of vegan fertilizers.