Why I stopped using coffee grounds in my raised beds

Everyone swears by used coffee grounds for soil, but after 3 months of adding them, my zucchini got yellow leaves and barely grew. I tested the soil pH and it dropped to 5.0, way too acidic for veggies. Has anyone else had this issue with coffee grounds backfiring?

2 comments

2 Comments

wesley3857d ago

Oh man, that exact thing happened to me with my tomatoes last year. Coffee grounds are great in small amounts mixed with browns, but too much will nuke your pH and mess with nitrogen levels. I'd suggest laying off them for a bit and adding some garden lime to bring things back up.

gibson.sarah7d ago

Yeah, my neighbor told me the exact same thing after I dumped a whole bucket of coffee grounds around my blueberry bushes last spring. Thought I was being clever, turns out I was just nuking the soil. What finally worked for me was a mix of dolomitic lime and letting the pile sit for a solid two months with nothing but shredded leaves and grass clippings. Tested the pH after that and it was back to normal, plus the plants bounced back pretty quick. Your advice about keeping the grounds small and mixed is spot on, took me a whole season to figure that out the hard way.