[that would be the sound of the worms slithering out of the can]

you aren't missing much at all. If it does help at all, it's paltry and insignificant compared to regular fertilizing. Particularly because orchids are not heavy feeders to begin with. It's not worth it for the average hobbyist to worry about. Little if any gain.

Another question where i do not know the answer, but i end up watering the leaves anyway.

Every paltry and insignificant bit helps the effort.

If my plant flowers with 6 buds this year instead of "only" the 5 of last year, I choose to view the improvement as an increase of 20% ! That seems much more impressive than only one additional flower. :)

--Stitz--

Terp how do you or would you apply fertilizer to a mounted plant? If they were watered with pure water and planted in inorganic media would you feed them? Would they be heavier feeders if you fed them more?

There, I contributed to the can of worms :>)

Brooke

If you do want to foliar feed, spray the underside of the leaves, where it will do the most good. I agree with arthurm, I don't know the answer, but I foliar feed anyway. I especially do after heavy rains when the plants are outdoors, and I want to feed the orchids but I don't want to contribute any more water to the media.

Sorry this is brief, I'm in a hurry:

brooke:
I soak them in the sink.
Yes I would feed them. they wouldn't get any nutrients otherwise.
No. they're ability to absorb nutrients is not a function of how much you decide to apply. Its a function of how much they need, which isn't much. I know you know that, so your point on this question is unfortunately lost on me .

Orchid: If you're spraying the leaves, where's the runoff going? Down into the pot.

Just like spraying your plants to raise humdity, its not really doing harm, so if it makes you feel better doing it, go for it. But orchids stomata are closed during the day because of their metabolic/photosynthetic pathway (see CAM plants), when we are apt to feed them, so it won't get absorbed.

Terp, I don't spray heavily enough to produce run-off. Actually it's only a very fine mist. And I don't spray with fertilizer, I spray with liquid seaweed.

Terp I'm in a hurry too but shall try to reply to your reply.

There has been many studies done on orchids and their ability to close their stomata when the temps got above 90 to preserve the moisture in the plant. If it closes when the temps go above 90, they must be open below that temp.

The CAM orchids you refer to would probably be the ones growing in a very arid, hot climate i.e. Brassavola. Some Brassavola have a wax coating to reduce the temp of the plant and some have terrete foliage which draws up to conserve moisture. They uncurl when moisture is adequate. This is not needed in an area with constant moisture in the air. If the temp doesn't go above 90, then the stomata has no need to close to reduce transpiration. This would be orchids without pbulbs that must rely on humidity for part of their water needs.

Some of us have too many mounts to soak and they must receive moisture and nutrients via a hose, wetting the mount and the foliage.

You really don't have to apply fertilizer - functioning roots and leaves with correct moisture and light will permit the plant to grow and bloom but if fertilizer is applied the plant will perform better. A heavier application of fertilizer during the active growth period will certainly inhance the process with less or none needed during their dormant season.

If you can take a Phal with no roots, totally submerge the leaves in fertilizer water a couple times of week and regrow roots, foliar feeding must work. During the process of regrowing roots the leaves stayed totally hydrated and also continued to grow additional leaves. If the Phal wasn't absorbing nutrients and moisture through the leaves it would have dried up like a prune.

My answer to the original question is yes, I totally believe in foliar feeding in addition to the normal application to the roots.

Brooke

I have had dramatic results with foliar feeding the plants that I keep outdoors. After years of sparce blooming, I tried spraying the underside of the leaves with weak orchid solution. Instead of just one or two of my plants blooming, I had eight or nine with multiple spikes. One plant alone had five spikes at one time. Wow, what a difference. It may be coincidence but I will not stop foliar spraying.

After using conventional fertilising methods for the last thirty years with varying degrees of success I have begun to use a foliar spray. Actually two sprays: one to promote growth and one for flowering. It was reccomended to me by a commercial grower and retailer (one of if not the largest in SE Queensland). It is simply mixed with water in a very weak solution and sprayed on weekly using a misting type sprayer. I have posted a link that may be of assistance. http://www.fameorchids.com/fertilizingprogramme