Ken, great research there. I'm just about to the tomb stage from reading tomes, too.
I sent an e-mail to the authors of my orchid book, and got a response from Tom Sheehan, professor emeritus in environmental hort at UF. He sounds like a very nice fellow, and certainly has some creds but he only muddied the waters for me by adding his weight to the "doesn't matter" side of the argument. Here's what he said:
"Elaine, Glad to hear that the orchid bug has bitten you and unfortunately there is no cure and one just continues to expand one’s collection ad- infinitum. Good luck with yours.
With regards to your orchid fertilizer question, I have seen the same information on urea printed in a number of orchid books, yet am not aware of any definitive work in this area. In all my 70+ years of growing orchids I have found that orchid fertilization is the most controversial part of orchid culture with each grower having his own special fertilizer or fertilizer program. Since orchids grow in a wide variety of media, it is difficult to come up with a specific fertilizer for all orchids. I have always been of the opinion that any balanced (NPK) fertilizer used as recommended on the container is usually adequate for the majority of the orchids grown today. As a matter of fact, my present fertilizer program in my greenhouse consists of bi-weekly application of Miracle Grow, using there proportioner. I always irrigate the next day to wash the excess nutrients off of the leaves to prevent green algae from growing on the foliage. Basically, I am folia fertilizing my orchids and they do very well."
So, as far as I can see there are arguments for both sides here, and people who succeed with both kinds of fertilizer. So as you pointed out, curiosity has its bounds and mine is there. Other than carrying out my little experiment with my four little guinea pig orchids, I think I'm going to let it go. Maybe every week or two I'll update progress with pictures of the four victims, looking for signs of new growth or color change. At least I can satisfy myself that for those orchids, in my garden, in summer in Florida it either does or does not make any difference where they get their nitrogen.
