Many of us have probably put used coffee grounds in our soil to boost plant growth. But are they really good for our soil and plants?
Let's look at some pros and cons of adding used coffee grounds to your soil mix:
Pros
Add nutrient to soil --> improves drainage, water retention, and aeration in soil (Gardening Know How)
Benefit microorganisms helpful for plant growth and attracts earthworms (Gardening Know How)
Supercharges acid-loving plant growth (e.g. blueberries, azaleas) (Healthline)
Cons
Too much coffee grounds in the soil can have harmful effects...
Increase soil acidity, which can damage plant growth (Gardens Alive)
Have antibacterial properties, which can repel beneficial microorganisms (Science Direct)
Look at the pros and cons, it is pretty clear that adding used coffee grounds to your garden is a double-edged sword. A little too much coffee grounds can cause a huge negative impact on your garden. Fortunately, an adequate amount of used coffee grounds can bring many great benefits to your plants.
So, the lesson is: coffee grounds can be beneficial to our gardens, as long as we are careful about how much of them we add to the soil.