Hi RamPuppy,
Well thank you, flattery will get you everywhere!
I use Osmacote (Dutch manufacturer) 10:11:18 + 2 MgO, slow release (6 month type). It can either be mixed in with the media or just sprinkled on top. Most species absolutely love it. Some like it quite a lot, some are indifferent and some (a very few e.g. N. argentii in particular) don't seem to like it at all.
But (and this is a biiiiiig BUT) is that we water from above very heavily. This is essential to prevent buildup of salts around the roots which will burn the roots eventually if not washed away regularly. We only use this type of fertilizer since we have the right conditions for it and it works better that foliar feeding, probably because we water so much. The reason we water so copiously by the way, is to try to emulate natural conditions since it rains a lot in most Nepenthes natural habitats. Water flowing past the roots also washes away certain chemicals that the plant excrete through the roots.
I have read Jeff Schafer write words to the effect that these plants developed carnivory for a reason and that feeding the pitchers with prey is the best way of feeding Nepenthes. I agree 100% and would love to feed all my plants naturally, but we have so many it's just not practical to do that. I have tried all sorts of whacky things. At one time we had many baskets of rotting fruit hanging all around the nurseries to breed fruit flies. It worked, especially for small seedlings with tiny pitchers that caught lots of flies. Then the rats moved in. Yum! Fruit to eat and plants in pots that could be chewed up to make nests, thank you very much! On one night we lost over 300 plants. The next night on another bench, every single plant had been chewed off at the base. On moving the pots we found several things like this:
So, no more fruit or fruit flies after that!
Feed your plants crickets, or use dilute foliar feed (about 1/4 recommended strength) but beware of root feeding unless you can flush it through regularly.
By the way, does anyone know where the miconception that Nepenthes cannot absorb nutrients through the roots comes from? Most Nepenthes develop pitchers to catch prey as an adjunct to absorption of nutirents through the roots, not as a total replacement. Those species that grow in peat-swamp-forest have peat-tea to drink which contains a variety of chemicals. It may be that some species (e.g. those that grow on laterite soils) absorb trace elements from the soil that are not present in sufficient levels in insect prey. Iron for example? Or calcium perhaps? we've tried everything from egg-shell water to chelated iron preparations. Some things work on some species and not on others. I'm not at liberty to tell all at this stage.
In case anyone is still awake and has read this far, here's another photo. N. spectabilis x ventricosa - an easy grower.
Bye,
Rob