Phals, s/h and short pots

[smokinjoe1952]

I have had several smaller Phals in 3" diameter pots that are only 2.5" high. After de-potting a couple, and noticing how poorly the roots were growing, I have come to the conclusion that the shorter pots sold with the 2 pot system are just too short. Even with a small amount of water in the reservoir, the initial root bed is about an inch or less from the water.

Also, some preliminary testing shows that the no longer sold PRIME AGRA may have been too good at wicking. Other brands seem to wick a little less.

I think in my case the combination of short pots and superior wicking PRIME AGRA proved too wet for Phal roots.

I transplanted a couple into an inch higher pot, and intend to put very little water in the reservoir. Time will tell.

I have a couple Phaphs that seem to do OK with a 2.5" pot, but it just seems like they would be too short for just about everything. My taller pots seem to work better for everything that is potted in them.

The attached picture shows the pot I am talking about.

I have re-potted an Onc. in a single tall deli pot, and will try a Phal in one soon.

SJ

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The thing I like about taller pots for any plant that grows long roots is that they can find the level at which they're happy. Too short a pot may give them a smaller happy zone.

[Ray]

There really isn't any such thing as a LECA that wicks "too well." In fact, the better the wicking, the less tendency there will be for root suffocation. Picture this scenario describing the conditions within the pot, bottom to top:

🔸In the reservoir, the particles are saturated, and there is absolutely no space between them that are not full of water.

🔸Move up slightly, and you are in that range where the particles are still saturated, and surface tension can hold the water well enough that the void space is still mostly full.

🔸Move higher still, and both the degree of saturation and filling of the interstitial spaces begins to decrease.

🔸Higher still, and there is zero interstitial "clogging" by the water, and the saturation decreases further.

🔸In an "infinitely-tall" pot, eventually you get to no water at all, as it has all evaporated, having outstripped the LECA's ability to wick it up fast enough.

If the LECA wicks well, that transition zone from the spaces being 100% full of water to 100% empty will be very short, making the "breathability" for the roots better, and the height of the column that still carries some moisture will be tall, but that last parameter is controlled by the conditions affecting evaporation rate, as well.

I will add that I now consider the moisture gradient allowing the plants to "find their own preferred depth" to be incorrect, as every plant I have ever grown in semi-hydroponics will eventually grow its roots right down into the reservoir, fully submerged.

All that rambling explanation out of the way, if the issues with the phals in the short pot is with established plants (i.e., they are roots that grew in that pot - we expect existing roots to fail when moved to s/h, and to be replaced by new ones optimized for the conditions), then there is another cultural parameter that's out-of-sorts.

If, on the other hand, these are the pre-existing roots that are failing, so what? (Unless it was moved into S/H at an inappropriate time.)

[estación seca]

When writing above about plants with long roots finding their preferred level in deep pots, I meant not only orchids, nor only S/H. I plant my sprouted cycad seeds in a pot called a Tall One made by Stuewe. It is 4" / 10cm square at the top and 14" / 36cm tall. With a heavier soil mix that stays wet longer, roots don't reach the bottom. With lighter mixes they may.

I find many orchids I move to S/H do not lose the roots they came with while they grow new ones. I think with my lower humidity, and my inability to water more than once a week, my wet-dry transition zones may be lower than those in more humid areas, even though my reservoirs usually don't go dry.

[Salixx]

I removed all my phals from S/H, they just didn't seem to like it, old roots died as expect but the new roots either went down into the media and died or went up into the air. Maybe my place gets too cold? I don't know, but are there other conditions that might lead the Phals to not do well?

[estación seca]

Originally Posted by Salixx

I removed all my phals from S/H, they just didn't seem to like it, old roots died as expect but the new roots either went down into the media and died or went up into the air. Maybe my place gets too cold? I don't know, but are there other conditions that might lead the Phals to not do well?

I can only think they were too cold. The evaporative cooling with S/H makes the root zone even cooler.

My Phals do much better in S/H than in anything else. My growing area in winter is heated to 60 F / 15.6C at night. I get away with this low a temperature because, even on cloudy winter days, it is well above 75 F / 24C by day, and into the 80s F / 27+C on sunny days.

Most hybrid Phals are warm-growing plants that only just tolerate typical indoor winter temperatures and darkness in cold areas. Have you tried putting them in S/H on a heating mat?

[smokinjoe1952]

I am also seeing old roots die, air roots like crazy, but no new root growth in the LECA. My air roots are now doing much better since I raised the humidity. I can only think it is my watering regimen, and the pot height causing no new LECA root growth.

My culture:

Enclosed indoor grow chamber.

Day = 78-80 degrees with 65% humidity

Night = 65 - 68 degrees with 75% humidity
(never lower than 65 degrees)

Phals on heat mat separated by 1/4" of plastic egg crate.

LED lighting for 14 hours/day during summer

K-lite at 25 ppm N at each watering

Kelpmax and Innocucor once month

I am not sure what it could be besides watering too much or pots too shallow. I have started watering only when the reservoir is dry, and only enough water to make the gauge just start to move. I understand that it will not be SEMI-HYDRO, but only growing in LECA as a medium, but that is what they might want.

Part of the fun of this hobby is problem solving, and the Phals have been problematic!

SJ

[Ray]

OK, now I'm pissed. (Not really..it's the wine talking.)

Folks who kill plants in sphagnum say "I have problems with growing in sphagnum."

Folks with issues growing in semi-hydroponics blame it on semi-hydroponics.

One needs to figure out the giant, complex equation of ALL of the cultural parameters it takes to be successful - for that particular plant. Failure in S/H culture is probably more YOUR failure (to provide ALL of the right conditions) than it is the medium or pot.

The plants want what they need. Not a specific any single aspect. They want it all, and it's our job to provide that.

OK. I'm off the soapbox now, and I'll go open another bottle of presecco.

[estación seca]

Originally Posted by Ray

OK, now I'm pissed. (Not really..it's the wine....)

... I'll go open another bottle of presecco.

Sounds like you'd be pissed on both sides of the Atlantic.

[smokinjoe1952]

Ray,

Not sure why you are pissed, but don't be because I am 100% sure it is my problem and not anything else. I am just trying to figure out what my problem actually is. Please don't misunderstand, my other orchid types seem to be doing well in s/h. I have un-potted several and root growth is fine. Your expertise, advice and Firstray products have helped me get to where I am in only a year.

For whatever reason, I am on the "need taller pot" for Phals kick, so will try that and see how it works out.

I THINK I am doing and providing just about everything that the phals want, but obviously...not quite.

You have stated many times that you can not grow "some orchid type" in s/h. I forget which one(s). But, with all you experience you must have an idea of what is wrong with your culture that makes things go wrong. I would like to see some thoughts on what specifically you think is out of whack for those that you can't grow. That may help me determine my Phal problem. I am willing to experiment, but if they continue to be problematic, I have no problem giving up Phals, as you did with your problematic orchids.

SJ