Coffe grounds in compost - Ask Extension
I just read the attached article which reports that coffee grounds inhibit plant growth, because of the caffeine still present in used grounds. I inc...
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Coffe grounds in compost #859912
Asked February 26, 2024, 1:26 PM EST
I just read the attached article which reports that coffee grounds inhibit plant growth, because of the caffeine still present in used grounds. I include coffee grounds in the kitchen waste that goes in my compost bin, and since I don't include much yard waste, the grounds might comprise as much as 25% by volume. Should I discontinue putting coffee grounds in my compost bin?
Larimer County Colorado
Expert Response
Hi Carol,
The research recommends that your compost be no more than 20% by volume coffee grounds. If you get to 30% or more, the effect on plants was detrimental to growth. So 25% is pushing it, and you may want to reduce that a little.
Here's a good article from Dr. Linda Chalker-Scott at Washington State: https://s3.wp.wsu.edu/uploads/sites/403/2015/03/coffee-grounds.pdf
It's not the caffeine that causes negative effects on plants, but other components in the coffee grounds.
The research recommends that your compost be no more than 20% by volume coffee grounds. If you get to 30% or more, the effect on plants was detrimental to growth. So 25% is pushing it, and you may want to reduce that a little.
Here's a good article from Dr. Linda Chalker-Scott at Washington State: https://s3.wp.wsu.edu/uploads/sites/403/2015/03/coffee-grounds.pdf
It's not the caffeine that causes negative effects on plants, but other components in the coffee grounds.
