I for one find your using orchid fertilizer as part of you common standard of great value. Pouring coffee over unfertilized plants only tells us that coffee carries fertilizer values, something plant growers have known for years.
Whether it has some other qualities that affects Neps (or other CP's) growth "other than" it's fertilizer value is still yet unknown (Like the acids in the coffee, or some other component.)
So while some people feel the experiment is less than ideal under the circumstances, I feel it is actually more appropriate. (Comparing a plant receiving coffee treatments to one totally starving, would only illustrate what to me would be expected already. But at this point your experiment addresses the next obvious question, which hasn't been looked into yet.)
Concerning the sphagnum, are you applying coffee to the sphagnum itself or pouring the coffee thru it... and more importantly, are you applying it the same way as you do when applying the fertilizer? (I am curious if the coffee/fertilizer is having affects when applied to the "growing parts"/"leaf zone" of the sphagnum as compared to the "lower portions"/"root zone".) This could have bearing to when people experience "burn", algae, etc. when they do it.
While some people have had fertilizer burn to sphagnum, I have lately had rather good growth from it, unexpectedly.
Well, keep up the experiments. I am interested to see the results long term.
Oh yea... Are you photographing the 18 subjects for posting later? Also, I looked but couldn't find... aside from the initial coffee treatment, do you plan on doing the coffee treatment on a regular basis? If so, how far apart? (If you already mentioned, I am sorry I didn't see it... mind ain't working well lately.)
Well, good luck. It is nice to see you can afford to experiment on such valued plants. Makes seeing the results that much more interesting!
Thanks . . .
The way things were worked out was more out of necessity than carefully planned, since I only had a few plants available to experiment upon; and I had already been using 1/4 strength 30:10:10 orchid fertilizers on all of the Nepenthes for several years.
I applied the coffee in the same manner as the fertilizer, by pouring it through the media -- over the plant leaves themselves -- until it visibly drained, as one would conventionally water any plant. Initially, I was somewhat concerned about algal growth, though I had never experienced a problem or damage to the sphagnum moss with the dilute fertilizer in the past; but I was worried about the possible effects of the added coffee.
There turned out to be no need for concern, and I immediately noticed a marked increased growth of the sphagnum within ten days of the coffee application -- and, visibly, more rapid growth of the plants themselves (notable because most of the highlanders, otherwise, develop very slowly).
I have only applied the coffee once and the most current recommendation is treatment every six months; provided that no harm comes to the plants, I will continue using it. The 30:10:10 has been applied biweekly throughout this time.
I will post photos of the other -- eighteen -- subjects down the line; whether I can "afford" to experiment on them remains to be seen. I honestly don't wish to kill my plants or attempt to replace them . . .
I am also awaiting a shipment of more -- expendable -- Nepenthes seeds to more formally experiment upon . . .