Tom Broome (cycadjungle) wrote an article called “Coffee, Cycads’ New Best Friend?” <--- that's a link
He has also used it with his pepper plants and has conversed with Ramon (walkgood) about it in his 2013 Glog. Ramon went on to conduct some experiments with it. you can read about it starting here: http://thehotpepper.com/topic/36338-walkgood-2013-to-2014/page-24#entry788508
You can also read where Tom chimed in starting here: http://thehotpepper.com/topic/36338-walkgood-2013-to-2014/page-24#entry788636
Personally, I like using coffee in my soil mixes. It's a great source of Nitrogen, I typically use about 10% coffee, I pick it up from Starbucks, in my soil mixes and have added it to my compost teas also. The important thing is to keep it fresh. Don't use coffee that's more than a week old and if your not going to use it right away then freeze it till your ready to use it.
He has also used it with his pepper plants and has conversed with Ramon (walkgood) about it in his 2013 Glog. Ramon went on to conduct some experiments with it. you can read about it starting here: http://thehotpepper.com/topic/36338-walkgood-2013-to-2014/page-24#entry788508
You can also read where Tom chimed in starting here: http://thehotpepper.com/topic/36338-walkgood-2013-to-2014/page-24#entry788636
Personally, I like using coffee in my soil mixes. It's a great source of Nitrogen, I typically use about 10% coffee, I pick it up from Starbucks, in my soil mixes and have added it to my compost teas also. The important thing is to keep it fresh. Don't use coffee that's more than a week old and if your not going to use it right away then freeze it till your ready to use it.