By POLKA at 2010-02-11 00:55
Weekly, Weakly May Be Best
I have come to believe that there is a critical point in time in which you should give careful attention to fertilizing your orchids.
I recently read the article Flower Induction in Orchids, by Ms. Marilyn Light (©2002). She reported that orchids, being monocots, have in their new shoot buds everything prepared for growth, foliage, and flowering just like the embryonic plants found in other monocots such as the heart of tulip bulbs.
Therefore, I conclude that the most important time to fertilize would be from bud break until the new shoot is one third to one half mature. It is in this early stage of growth that the new buds are forming. So then, it seems that the most critical time to fertilize any orchid is when the new shoots are beginning until they are at least one-half grown, for by then, the next season’s buds will have been completely formed.
Now, continuing a fertilizer program all year long allows the plant to completely mature all parts present to their fullest potential, especially the flower buds, which is why we grow them. And, if the orchid plant had excellent growth the previous season, then you should have an excellent potential display this season.
Maturity of every part is the important thing. Therefore I believe it is a consistent fertilizing program that brings out the best in our orchids. And, indeed, weakly weekly may still be the very best advice to use, regardless the type of fertilizer you choose, and I think that this is the reason why it works.
So, what to use?
Orchid plants are opportunists. In nature, they sit there perched in a tree taking whatever comes their way. They cannot search for nutrients in the debris surrounding their basal roots. They have no root hairs. They are forced to take whatever comes their way.
Now, I do not think the urea versus nitrate thing is as important as one might suppose. All plants have enzymes to help break apart large molecules down into smaller components. Proteins found in the decaying matter and urea (which is the first step in protein breakdown) are large molecules. Ammonia, which comes next, and the nitrate/nitrites which come along later are smaller still and more easily assimilated.
Think for a moment. How many of you use fish emulsion, sea-weed, bat guano, compost tea, or similar products for your orchid fertilization? It usually works, does it not? The orchid can take these raw ingredients and through enzymatic action assimilate them and process them. They absorb what touches their root velamen. So, if you buy the nitrate-only orchid fertilizers, your orchid will not have to work as hard to use the materials.
Regardless, I believe it is critical that if you choose to fertilize, make every effort to do so early in the new-growth phase for optimum potential of your orchid collection.
Rex W. Ulmer