LECA surrounded by Sphagnum

[Ray]

Originally Posted by WaterWitchin

I'd agree with that one... using sphag along with LECA, even if you keep it sort of divided (like sphag along the perimeter of pot and LECA in the middle, would end up needing repotting way more rapidly. When I first read about this, all I could think was what a yucky mess that would be a year down the line. Sort of ruins the idea of not having to repot often.

...which is why I've started using rockwool cubes, instead

[WaterWitchin]

Originally Posted by Ray

...which is why I've started using rockwool cubes, instead

Same. But jury's still out here. I usually reuse my LECA at least once. Haven't had the need or opportunity to repot anything yet that has rockwool cubes in it. It will be interesting to see how much hassle it is to remove the rockwool to reuse the LECA.

[Shadeflower]

to me the way a self watering or semi hydro pot should work is that the top layer always stays dry and everything else below is damp. Whatever substrate, this is what I try to aim for. It has to be airy but wick enough water to the top - but not all the way to the top, this is important. If the top layer stays too damp and algae starts growing then in the environment you are in the media is too wicking.

In my climate this never happens with lecca, it wicks but dries fast on top so I need to add a more wicking layer. I've not tried rockwool yet but the principle is the same, keep the lecca just a bit more evenly damp but if the top layer stays damp then there is too much wicking action in the pot.

Like I said I never have lecca stay damp for too long but I have sen pictures wehre it seems to be happening to other people usng semi-hydro. You can adjust the level of dampness in a pot by adding holes or using bigger pebbles (which adds more air pockets).

To me it is about finding just the right level of moisture throughout the pot which is very tricky as Ray recently pointed out how just tiny changes can make a big difference, eg just adding a hole into the side of the pot for example can be the difference between good or bad growth all year. But one has to find that level through trial and error and I think it is important to stress how constant water is important but too much can suffocate the roots, not that the plant will die, but it does reduce growth. Roots that have access to constant water but can breathe well at the same time grow the best.

Ps: this only applies to semi-hydro or self watering pots as with manual watering the gardener watches the humidity level and waters accordingly so the principle is very different to watering by hand where one tends to overwater a bit and then let it dry completely before watering again.

[SouthPark]

Originally Posted by Ray

Some aerial roots take to being submerged in media or water well; others do not. Why? Your guess is as good as mine.

I generally and previously assumed that most orchid roots that grow in regular/classical growing media (such as air, or rocks, bark, charcoal, perlite, or a mix of these) have a good chance of not making it if they are transferred to a water or very watery medium - due to the roots not being adapted to handle lower oxygen environments. So may end up drowning after a while.

I haven't seen what happens though - if existing regular roots are allowed to naturally grow down into a water medium though --- as in whether that portion that goes into the water can adapt and survive. Maybe they can. I might have to give this a try in future, such as choose an aerial root that is outside the pot, and put a see-through pot (filled with water) just underneath ----- and see what happens if the root grows into the water.

As for transferring aerial roots directly into water (submerging ------ along the lines of 'water culture' method - but involving unadapted roots) ----- I was assuming that unadapted roots (of say catts or phals) may not make it ----- which is why the general method for growing in watery environments involves allowing brand new roots to grow from the rhizome or stem when those brand new emerging roots are very close to the water already, or even in the water already ----- so that some adaptation process can occur.

I wouldn't be surprised though - that some aerial roots can handle an abrupt change from an air to a watery environment though ----- as the plant and animal world always offer nice surprises! I know that (even though not orchids) ------ plants like dracaena sanderiana ----- have roots that can handle abrupt transition from soil to water.

[Ray]

Originally Posted by Shadeflower

to me the way a self watering or semi hydro pot should work is that the top layer always stays dry and everything else below is damp. Whatever substrate, this is what I try to aim for. It has to be airy but wick enough water to the top - but not all the way to the top, this is important. If the top layer stays too damp and algae starts growing then in the environment you are in the media is too wicking.

My S/H plants have always done best if the LECA is uniformly and constantly wet. There is plenty of air flow in the void space between the pellets, and the absorption and wicking characteristics means that wet or dry, the open volume is more or less that same.

A disadvantage of any of it drying out is the precipitation of minerals.

[WaterWitchin]

Originally Posted by Shadeflower

to me the way a self watering or semi hydro pot should work is that the top layer always stays dry and everything else below is damp. Whatever substrate, this is what I try to aim for. It has to be airy but wick enough water to the top - but not all the way to the top, this is important. If the top layer stays too damp and algae starts growing then in the environment you are in the media is too wicking.

In my climate this never happens with lecca, it wicks but dries fast on top so I need to add a more wicking layer. I've not tried rockwool yet but the principle is the same, keep the lecca just a bit more evenly damp but if the top layer stays damp then there is too much wicking action in the pot.

Like I said I never have lecca stay damp for too long but I have sen pictures wehre it seems to be happening to other people usng semi-hydro. You can adjust the level of dampness in a pot by adding holes or using bigger pebbles (which adds more air pockets).

To me it is about finding just the right level of moisture throughout the pot which is very tricky as Ray recently pointed out how just tiny changes can make a big difference, eg just adding a hole into the side of the pot for example can be the difference between good or bad growth all year. But one has to find that level through trial and error and I think it is important to stress how constant water is important but too much can suffocate the roots, not that the plant will die, but it does reduce growth. Roots that have access to constant water but can breathe well at the same time grow the best.

Ps: this only applies to semi-hydro or self watering pots as with manual watering the gardener watches the humidity level and waters accordingly so the principle is very different to watering by hand where one tends to overwater a bit and then let it dry completely before watering again.

Well, huh. Interesting ShadeFlower. Because I strive for the opposite. I want that wicking clear to the top. For many, I can accomplish that with where I place the reservoir and hit the sweet spot. But sometimes I can't, or I have a different plant potted in the same vessel now, or it's an older pot where I didn't drill with the accumulated knowledge of where I needed the reservoir placed for my climate.

I use the rockwool on ones where, due to the variable, it no longer stays wet at the top. Granted, the very top layer of LECA won't stay damp when I have a lot of airflow, or humidity is a little lower in the winter. Fortunately, most of mine put out new roots in the more humid months here anyway.

I get algae on many of my pots, because they're all glass or fairly translucent plastic, but more toward the middle and not the top. I don't worry about algae.

Would you explain why you don't want the top part to stay damp? I'm not being a smart-aleck. I don't understand the why of it.

[Shadeflower]

WW, let me just start by saying that no matter what I say I know I will not change your methods.
Just like I wouldn't change mine. Once we have found what we are happy with - rarely will we throw it all out, repot the orchid (woot) and try something different so just to humor you since you asked, although I already answered your question the main reason is because wet roots don't grow as well as dry(ish) roots. Not bone dry but if the roots are so wet that algae grows on them then it is too wet and the orchid will grow slower than if it were kept just a touch drier.

The other important reason for me is that I can accept if roots rot at the bottom but I cannot accept the stem starting to rot so that is another very important reason to keep the top half a cm dry.

The following picture shows a pot that was kept too wet, the result has been reduced growth. The roots haven't died although they could be looking a lot better too but it was being kept too wet. I can't justify how I can tell that one orchid is growing faster than another so you will have to take my word for that I'm afraid, or not as I stated at the beginning

It's generally best to try different things and make ones own conclusions.

edit: as a ps: It seems to matter more with cattleya's than with phals, phals do not seem to be affected by lots of moisture in the pot in the same way a cattleya would be in my experience so it does depend on the orchid a bit too.

[WaterWitchin]

Originally Posted by Shadeflower

WW, let me just start by saying that no matter what I say I know I will not change your methods.
Just like I wouldn't change mine. Once we have found what we are happy with - rarely will we throw it all out, repot the orchid (woot) and try something different so just to humor you since you asked, although I already answered your question the main reason is because wet roots don't grow as well as dry(ish) roots. Not bone dry but if the roots are so wet that algae grows on them then it is too wet and the orchid will grow slower than if it were kept just a touch drier...

Well, thanks for humoring me. You're correct. I won't ever throw the baby out with the bathwater. Neither should you. I'm not much of a follower of another's methods, because we all have so many different environments/climates. Wanted to understand why you said what you said, and wanted more insight into what you were saying, and why. It makes sense, for your climate and environment.

So I guess gracias for taking time to explain. I try to understand what folks in different environments do, and why. This explains it.

[Leafmite]

Maybe instead of moss, use a loop of cotton rope (sold as clothesline) to help wick up the water.

[katsucats]

I'm with Shadeflower, but more out of maintenance cost than anything. For me, it would take too much energy to keep the top layer moist all the time. I'd prefer that the roots grow down anyways, and frankly, I don't see why it should make any major difference whether the top layer is dry. Minerals that precipitate to the top might be ugly, but the top of your substrate is hardly in contact with the plant at all.

I will also point out that putting a top layer of moss is practically the same in concept to Isurus' PET method. I've also seen it suggested for growing the likes of Bulbophyllum. It seems to work fine when I've tried it to keep the top layer moist, but I don't bother anymore.

I'm also looking into using a nylon rope to help distribute water more evenly, but first I'd need to find a suitable outer pot to provide a deeper reservoir for more benefits.