Hi Jeff,
Europe was fine thanks. Great weather for a change, although a bit of a rush since it included Germany and the UK into a 6 day schedule.
We've just completed a 6 month trial using several fertilizers. The results for the best of them are written up and will be published shortly. Possibly on Pete Thiel's CP E-zene if he'll accept it. We now use this particular fertilizer universally, but detailed measurements were only taken for 3 species plus a control. Unfortunately, N. lowii wasn't in the trial, we used N. bicalcarata, N. sanguinea and N. rajah. The results for the fertilizer containing 2% MgO far outstripped the others, including an identical fertilizer without the MgO.
Frequency of application: once every 2 months in the lowlands and every 4 months in the highlands.
Type: Slow release Osmacote 10:11:18 + 2MgO + TE
Method of application: Top dressing.
Strangely enough, I've just visited one of the best (if not *the* best) private Nepenthes collections in Germany, that of Christian Klein and he was using precisely the same fertilizer but applied in a different way to avoid killing the sphagnum on the top of his pots.
Uh! Oh! I guess this may inadvertently open a debate as to whether root feeding of Nepenthes works. I'm quite certain it does, and have empirical data now, but you have to water from above (a lot) to prevent problems of salt build up around the roots.
One caution: A very few species really don't like this particular fertilizer and may still prefer to be foliar fed. N. argentii is one of these. This fertilizer produces good growth in that species but with bright yellow leaves and no pitchers. Ugh!