Q.Heather Rhodes Article On Coffee Grounds
I live in Las Vegas where the pH of the soil is 8.0 – 8.4. Heather Rhodes says in her article “Many people feel that coffee grounds lower the pH (or raise the acid level) of soil, which is good for acid-loving plants. But this is only true for unwashed coffee grounds. “Fresh coffee grounds are acidic. Used coffee grounds are neutral.” If you rinse your used coffee grounds, they will have a near-neutral pH of 6.5 and will not affect the acid levels of the soil. What regions and soil types are Heather speaking about in this article? Surely, 8.4 is effected by 6.5 pH. Yes? Thank you. Laura Glismann Read more at Gardening Know How: Composting With Coffee Grounds – Used Coffee Grounds For Gardening https://www.gardeningknowhow.com/composting/ingredients/coffee-grounds-gardening.htm
Certified GKH Gardening Expert
Yes, if your soil is that alkaline, then washed coffee grounds would, slowly, affect that pH. However, if you would like to lower that pH quicker- I would leave them unbrewed or rinsed. If you want better control, then I would opt for a product such as superphosphoric acid for that.