I plan on using coffee grounds as a mulch as it has quite a few benefits. But I want to know what the negatives of this could be or if anyone has used coffee grounds as mulch and had a negative effect on their garden. This is the best source for info on the effect on coffee grinds I could find http://www.puyallup.wsu.edu/~linda chalker-scott/horticultural myths_files/Myths/Coffee grounds.pdf it's from an accredited university, I don't trust bloggers and their narcissistic views, if you do state something please try to use a citation from a scientific source not a random bloggers view.
There was a guy in the downtown area of Vancouver B.C. that was taking all of the coffee grinds from the local Starbucks. He ammended the soil under an overpass....It may have been under the Granville Street bridge, or one of them in that area around False Creek. Mike McCardell on Global TV visited him for two or three years in a row. He was growing a very nice vegetable garden. I haven't seen any-thing about him yet this year.
Here's an article about it that I found from Washington State University. Sounds like it's a good idea. I'll certainly try it. We drink a lot of coffee. Here's another article about the chemical analysis of coffee grounds prepared by the Soil and Plant Laboratory in Bellevue, WA for Sunset (Sunset Books).
For a few years I regularly took the used coffee grounds (probably a third of a standard garbage can/week) from the local starbucks and spread it on my veggie garden. Can't say it did anything special as it was one of many additives I put into the soil, but it sure didn't hurt anything, as I always have had good success. I always joked that it would make the worms stay awake and work harder:)
As Linda's article says, just make sure you don't use them as straight mulch. Used straight it'll compact and impede airflow, the opposite of what you're trying to achieve. I use ours in the compost bin and it goes in Melitta filter and all.
This study may be of interest: Weed Suppression Through Three Mulches (Subterranean Clover, Coffee Grounds, Newspaper/straw mix) on a Swiss Beet Chard Crop.
Ya, if you hit up any starbucks in the afternoon they are more than happy to give you a garbage full of their coffeegrounds/paper filter waste. I did this a lot in Victoria, but sometimes you may need to ask in advance and tell them you'll be back in a couple of hours.
Yes they can be real stuck up when you ask for used coffee grounds, I had to show them on their own website that it states they give out grounds for gardens for free.
