LECA surrounded by Sphagnum

[Ray]

Originally Posted by katsucats

I don't know that roots would instantly die upon meeting mineral deposits touching the velamen. At least in my experience, this has never happened. Mineral deposits are more visible on LECA, but I can't imagine why any other medium wouldn't also have them, including medium that must dry between watering, like bark.

It’s not so much the mineral deposits as it is the porosity of the LECA, and that’s mostly an issue to the surrounding environment.

If the LECA is quite dry, it can literally desiccate a root tip that comes in contact with it.

[SouthPark]

With LECA ----- it is pretty good at wicking. So it might be like an elevator or conveyor belt ----- where the chemicals are in solution form, and the direction of travel is upward ----- and then it gets to the dry region and precipitation occurs ----- or turns into solid form up the top, and accumulates.

The bark etc probably doesn't have the same sort of movement. But I think that ------ too much of anything (too much fertiliser ----- or too frequent application) --- is not good for the orchids.

[SouthPark]

True - and that's where it all goes back to the area of checking to make sure that the growing environment and conditions remain satisfactory. So what could be done to prevent the LECA from drying out too much up top ------- which could involve adding particular materials (rock wool etc), or even machine systems for humidity control etc.

[Clawhammer]

My most successful s/h plants are ones that develop a layer of moss on top. Flushing every day and adding a little sphag/rockwool to the top layer of LECA expedites this process.

My s/h rockwool experiments have gone pretty well so far. I would probably recommend it over sphag.

[WaterWitchin]

I wish I could get moss to grow on the top of my pots. Then again, I'm sure no water-every-day kind of person. Never tried using sphag in SH, because it seemed counterintuitive. I started using LECA in SH for the inorganic and less repotting, plus no guessing about when to water. There are easier ways to solve the dry line by experimenting other than adding an organic material.

The rock wool, I agree, so far it appears to work well. I'm finding I do only prefer adding it to plants that are "thirstier" rather than all. Keeps me from having to water in between times when I WANT to water.