Despite the beneficial properties, some substances in coffee grounds can inhibit plant growth. Coffee grounds can be a useful fertilizer when used properly.
In the article we will talk about the pros and cons of coffee grounds for indoor plants.
Pros of coffee grounds as a fertilizer
Nutrients
Brewed coffee grounds retain some protein, oils, and carbohydrates.
Proteins, in turn, are rich in nitrogen, useful for plants.
In addition, coffee grounds include potassium, calcium, iron, magnesium, phosphorus and zinc.
Disease protection
Studies show that coffee grounds inhibit harmful microorganisms in the soil.
For example: fungal diseases.
Cons of coffee grounds as a fertilizer
Reducing plant growth
Studies were carried out on weeds and on some types of indoor plants.
The results suggest that coffee grounds can reduce plant growth.
Moisture barrier
Finely ground coffee grounds compact and prevent moisture from reaching the roots.
Therefore, coffee grounds are not recommended to be used as mulch.
How to properly use coffee grounds
The most effective and safest way is to use compost with 10-20% coffee grounds content.
Add a thin layer of compost to the potting soil 1-2 times a year.
A thin layer of coffee grounds with compost does not prevent moisture and air circulation.
