nobilior/walkeriana in sphagnum?

[ChrisFL]

Thanks Jerry. I'd really love for Mauro Rosim to chime in on this thread. He grows these species very well in sphag, and I'd love to hear his hypothesis has to why it works so well for him, the Japanese, and many South American growers.

[Rosim_in_BR]

Originally Posted by ChrisFL

Thanks Jerry. I'd really love for Mauro Rosim to chime in on this thread. He grows these species very well in sphag, and I'd love to hear his hypothesis has to why it works so well for him, the Japanese, and many South American growers.

Sorry Crys, I hadn't noticed the thread before.
You know, there's a lot of information passed on as absolute true on these two species... but there's not such thing as absolute true when orchids are concerned. Walkerianas and nobiliors in the wild pass through seasonal dry periods when it scarcely rains, but there's generous dew during the nights. On the other hand they face torrential rains almost every day during the wet period. So, what is good for them, the dryer condition, or the wetter? Of course they have to deal with both in the wild, but I personally think that we, as orchid growers, should look for the best our orchid can do and one of the most important, if not the most important thing is the water. If the plant can be kept so that it can benefit from a constant and balanced source of water in the roots (eliminating, or reducing the dry periods to the minimum) then it has 80, 90% of its needs available to try to reach its full potential in terms of growing speed, size, health, flower count and so on (as you know, an orchid is 90% water, 9% hydrogen, Oxygen and Carbon and 1% a bunch of other chemicals). I believe that orchids in nature, like walkeriana or nobilior, try to adapt themselves to survive in an environment that not always is the best for them. These two are adapted to stand a dry period of five or six months a year, but this does not mean we want to reproduce these stressing conditions in our artificial growing greenhouses. On the contrary. we have to avoid them whenever we discover how, because in nature there are a lot of compensations that we most likely are not providing in our artificial environment. It is with this idea in mind that I use moss as my first choice medium, with amazing results I must say. This medium, if the watering is correctly managed, has a humidity curb that provides almost a constant source of water without rotting the roots. And that’s exactly what I want. I balance the watering to keep the moss slightly humid most of the time and I think this is the key.
But, I must say that pretty much the same results are achieved with no matter what other medium. Even though you have them mounted. In this case it is enough that you have them watered many times during the day and night.
Actually, we rely on substrates because most of times we don’t want to spend our days and nights spraying orchids! Fortunately, we have other things to do than keeping orchids humid!
So, it is not the moss itself, but the way it can hold water and make it available that makes it better than other media in my opinion. With it I have better control of the water. For all that, if you want to use moss you need to find the humidity curb it has in your area because then you will know how often to water. It would be useful for that to have a test pot with the same characteristics you have on those the plants are. The objective is to try to withdraw the drying curb you have in your growing conditions. You water the pots normally and then you periodically check the control pot out to see how the moss is in the middle, not only on the surface. By making this you will be able to establish a relation between the dryness you see on the top and what is occurring in the middle of the moss. You will need to make the experiment a number of times to establish an average for each season and then you have a guide. Just take into account that the plant is uptaking water, so the medium the plant is in tends to dry a little faster than the test pot.
Use clay pots because they are porous and help eliminating water excess. I scratch small peanuts off of larger Styrofoam pieces (white only) and mix with the moss (80% moss 20% peanuts ore or less) to help with the drainage. I also use Styrofoam chunks as drainage material in the bottom of the pot. Again, Styrofoam hardly gets wet and this helps reducing the humidity peaks that occur when you water.
BTW, 80% of all my orchids are planted in moss, none of them with poor results.
But I insist, the moss can be the bad guy if watering is not adequate.
My walkerianas and nobiliors (and so many other orchids) are answering very well to this cultural method.
Hope this is useful in some way. If you need anything more specific, just let me know and I’ll try to help. Sorry for the long post.

[ChrisFL]

Mauro,

I cannot thank you enough for that outstanding post. Very informative. I only ask for a few clarifications:

How often do you fertilize?

So then, you would say, if the moss is dry all the way through by the time you water again, you are not watering enough?

Also, with nobilior, do you give them a "dry spell" at all? If not, and they are kept watered throughout the year, what is the flowering cue? I have seen many people claim that the only way to get some to bloom is to withhold water for weeks and sometimes months on end.

Again, thank you,
Chris

[Rosim_in_BR]

Originally Posted by ChrisFL

Mauro,

I cannot thank you enough for that outstanding post. Very informative. I only ask for a few clarifications:

How often do you fertilize?

For nobiliors and walkerianas, three or four times a year Chris, depending on the growing pattern the plant is presenting (the moment the new roots are breaking out), but that's because I don't use chemical fertilizers. I use organic fertilizer in small amounts I put on top of the medium, generally near the back bulbs. I use to mix bokashi with the fertilizer (70% organic fertilizer, 30% bokashi).
If you use chemicals you need to assure the new roots are not going to have the tips burnt. Chemical fertilizers are salts and when they accumulate in the substrate, or when a drop of fertilizing solution dries on the root tips, they steal water from the nearest source they found, in these cases the water content of the root tip cells.
I left my experience with chemicals far behind, but when they were my choice I used to water with a 100 ppm Nitrogen solution of a balanced fertilizer for four times then I thoroughly watered my plants with pure water in the fifth to remove any traces of salt formation that could have appeared even with these mild concentrations.
I still use chemicals with my Vandas, but I always water them with pure water 15-20 minutes after the fertilization. Here, as with no matter what other plants, the idea is to avoid salt formation that could damage the root tips.

Originally Posted by ChrisFL

So then, you would say, if the moss is dry all the way through by the time you water again, you are not watering enough?

Pretty much that. I don't allow the moss to completely dry. I water again when it is almost but not completely dry.

Originally Posted by ChrisFL

Also, with nobilior, do you give them a "dry spell" at all? If not, and they are kept watered throughout the year, what is the flowering cue? I have seen many people claim that the only way to get some to bloom is to withhold water for weeks and sometimes months on end.

Again, thank you,
Chris

Here in my area the dry season coincides with less luminosity, shorter days and cold weather and because of this the humidity of a given watering lasts longer than the hot weather longer days . Nobilior blooms at the end of the dry period, so I naturally reduce the peaks of water because less watering are needed. The general result is that the plants stay a little drier for more time than in the hot, rainy time and this has been enough to make them flower. Just for comparison, I still have one nobilior mounted that receives the same treatment I give to my Vandas receiving water every single day (except when the weather is too much cold), I don't give it any dry period at all and it blooms beautifully every year.
But, you know, all these are only hints because it is your plants that are going to tell you the best way to treat them. Just pay attention to them for a while until you know what is the best and then relax .

[ChrisFL]

Thank you Mauro!

Originally Posted by Rosim_in_BR

I use organic fertilizer in small amounts I put on top of the medium, generally near the back bulbs.

What type of organic fertilizer do you prefer? Fish emulsion?

Just for comparison, I still have one nobilior mounted that receives the same treatment I give to my Vandas receiving water every single day (except when the weather is too much cold), I don't give it any dry period at all and it blooms beautifully every year.

I observed that this was the case when I grew outdoors in Florida. Everything was mounted and treated the same all year. I still got blooms from my walkeriana/nobilior.

Thanks!