S/H ultimately not for me

[MT-Phal]

After a year of having my phal struggle through S/H, I hate to say that I'm putting it back into coconut chips. I'm not sure why, but the roots which grew into the medium never really enjoyed the environment. They would begin to turn brown and eventually black after a few months and I couldn't figure out the reason for this. I utilized H2O2 and Physan, which may have kept them green for a longer period of time, but ultimately could not save the root. I think this is the best decision though I regret having spent the time and money on a failed experiment.


Well, moving on! I still have plenty of physan and MSU fertilizer left... will this fertilizer be okay to use in this medium? Any idea of what the proper solution mix should be?

[tucker85]

I don't have a lot of experience with s/h but last year I put seven phals in it as an experiment. After eight months four of the phals had done almost nothing. A little bit of root growth and almost no leaf growth. Two phals did OK but not great and one of the phals grew very well and is in bud now. I left the successful one in s/h and plan to keep it there as long as it does well. I repotted three of the others in coconut husk chips in clay orchid pots and three in sphagnum in plastic net pots. All the transplants are growing very well in the new environment. I let the plants get almost completely dry between waterings. I plan to transplant once a year because coconut chips and sphagnum retain fertilizer salts. My situation is different than most because I grow outdoors in south Florida. Good luck.

[Ray]

MT - low temperature is probably the biggest obstacle when it comes to phalaenopsis in S/H.

Phals are really "warm to hot" growers, and the evaporative cooling that occurs in the open, airy LECA medium can push the lower limits in the root zone unless you keep them on heat mats or grow more toward the hot end of their preferred temperature range. Your description of the root issues makes me think that's likely in your case.

Don't forget that "semi-hydroponics" is not a complete definition of orchid culture, but is primarily focused on water and nutrient delivery.

Fertilizer choice has little-to nothing to do with the potting medium or culture method. The MSU stuff was not designed specifically for S/H culture, but being a complete package, happens to be good for it.

[silken]

Ray, you just gave me an idea as to maybe why an oncidium I have in SH does not look happy. A friend gave it to me already potted in leica balls and she kept the other half herself potted in the same way. She says hers is doing well and mine looked happy when I got it a few months ago. But I am seeing a bit of yellowing and worry it will slowly die off. She grows it in her home over winter and mine is in a heated greenhouse. The greenhouse cools to about 55 or 60 at night and warms to 65 -68 in the day. As well, there is a fan blowing near it. Do you think that might be too cold for it? It's quite large, so I was tempted to lift out a portion of it and pot in cedar chips and moss and see which does better. I didn't want to do that in mid winter tho.

[Masdyman]

Originally Posted by MT-Phal

After a year of having my phal struggle through S/H, I hate to say that I'm putting it back into coconut chips. I'm not sure why, but the roots which grew into the medium never really enjoyed the environment. They would begin to turn brown and eventually black after a few months and I couldn't figure out the reason for this. I utilized H2O2 and Physan, which may have kept them green for a longer period of time, but ultimately could not save the root. I think this is the best decision though I regret having spent the time and money on a failed experiment.


Well, moving on! I still have plenty of physan and MSU fertilizer left... will this fertilizer be okay to use in this medium? Any idea of what the proper solution mix should be?

I grow in CHC & use MSU type feed and having good results. I feed @ every watering @ about 80 ppm N, I don't flush either. You need to find what ppm N is right for you and your conditions. I was at MSU recommendations of 125 ppm N early on but reduced this as in the UK day length is not that great to suit so is very different growing conditions to say someone growing in Florida.

[Donald]

I grow mostly in bark and sphag and was having trouble getting some phrags to bloom so I reluctantly tried s/h and to my surprise they all reacted very positively. I presently have a Phrag. wallisii (species - 'Dutch Treat x self)that I couldn't do anything with it is starting to bloom after 3 years. Thanks for the supplies Ray.

[MT-Phal]

Originally Posted by Masdyman

I grow in CHC & use MSU type feed and having good results. I feed @ every watering @ about 80 ppm N, I don't flush either. You need to find what ppm N is right for you and your conditions. I was at MSU recommendations of 125 ppm N early on but reduced this as in the UK day length is not that great to suit so is very different growing conditions to say someone growing in Florida.

Thanks, Masdyman. I suppose I'll keep my batch at 50ppm knowing how coconut chips tend to retain so much and I plan on letting my medium almost dry between waterings.

And Ray, I keep my phal on a heating mat 24/7 and regardless of cool winters or very warm Los Angeles Valley summers the roots which grew into the prime agra just wouldn't keep. I decided to go back to coconut after a root, which had grown two inches into the medium started to brown. Another root which had grown three inches into the medium during the summer is almost dead. Kind of a mystery, I guess.

[Ray]

OK, so cooling may not be the issue, buth the fact that they do OK in the summer and not in the winter suggests it has something to do with temperatures.

Taking another tack - How about your watering regimen? Water temperature, frequency, thoroughness, etc.?

[silken]

I water mine about once a week with rainwater that was collected and sitting in pails in the greenhouse. There is always some water sitting in the tray that it sits on. I don't know much about SH and wasn't sure how much water it should be in.

[MT-Phal]

Originally Posted by Ray

OK, so cooling may not be the issue, buth the fact that they do OK in the summer and not in the winter suggests it has something to do with temperatures.

Taking another tack - How about your watering regimen? Water temperature, frequency, thoroughness, etc.?

Ray, the roots within the medium fared no better in the summer than in the winter. They usually begin to fade within a few months of being there.

As for watering regimen, b/c the top dried fairly quickly in my dry apartment I watered every day at a solution of 50ppm. I usually flushed with regular tap water before using the MSU mix, which sat in a gallon jug so the water was room temperature. I don't know of the pH b/c I never had a tool to measure, but I used water filtered with a britta container if that makes any difference. Every couple of weeks I would flush with regular water and use a physan mix to kill any potential bad stuff. Maybe something down there was immune?

Either way, I still have plenty of PA so maybe I'll try it again someday if I ever get another plant.