Question
Hi I've seen this YouTube( Nepenthesis) talked about using the coffee treatment to fertilize his nepenthes and it looks like it has good results. But, he says to pour the coffee into the pot, then flush it out with water after about 1-2 days an I was wondering if it was safe. Can't you spray it instead? And  I'm
Not sure if it'll harm my nepenthes (vogelli, ventricosa black peristome, glabrata, and a spectablilis) thanks
         -Ian

Answer
Hi Ian,

Coffee acts as a mild organic fertilizer, and has a slight acidifying effect on the soil.  Being an organic fertilizer, it needs to be acted on by bacteria to release plant available nutrients.  For that reason it would need to go into the soil, and not a foliar spray.  Plain brewed coffee won't have much the plant can use directly without the bacterial action.  It won't harm plants as long as you don't get too crazy with it ("So a little is good, a lot must be great!").

Now, having said all that, we've tried coffee a couple times, and just haven't seen much in the way of results from it.  It didn't harm anything, but the results were less than or equal to using a standard good quality orchid fertilizer.  If you're in a warmer climate with a longer growing season, or have a good temperature controlled growing area (ours fluctuates too much in winter), you may have different results.  Here's a link to a discussion on this:  http://icps.proboards.com/thread/3994/question-on-coffee-treat-nepenthes

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.growcarnivorousplants.com