Healthy soil and sustainable growing

[yarrow@sfo.com]

Title: Re: [Livingontheland] Getting Worms to Till and Fertilize

 Ken Hargesheimer wrote:

[coffee] Grounds are acidic so it really helps soils that are above 7.  Adding organic matter moves the ph toward 7.  I changed my soil from 8.2 to 7.2 in two/three years.

No, coffee grounds don't acidify soil. Most of the acidity in coffee is removed during the brewing process.

Sunset magazine had Starbucks coffee grounds tested at Soil and Plant Laboratory Inc., Bellevue, WA, and the pH was 6.2.

http://www.sunset.com/sunset/garden/edible/article/0,20633,1208232,00.html

Starbucks had coffee grounds analyzed by the University of Washington,

College of Forest Resources in 1995, which found that used grounds have an average pH of 6.9.

Another study also found pH 6.9 and stated that the grounds have "a significant amount of buffer capacity - adding the coffee to either acidic or basic solutions drove both towards neutral pH [7.0]."

http://faq.gardenweb.com/faq/lists/soil/2002015354019975.html