Rock Wool Medium

[Ray]

Originally Posted by WaterWitchin

Why do you say that Ray? Because it’s doing what I want, which is decreasing the level of the dry line which is now almost nil. Please elaborate.

I view the individual cubes as being “mini-reservoirs” in the LECA column. With them scattered throughout the material, the distance the water has to be wicked is small, but in the layer you showed, it has greater distance to travel.

Maybe in your current conditions it’s fine, but if your conditions changed to favor really fast evaporation, it might still outstrip the wicking, driving the “dry line” down.

Sure, a mini-reservoir closer to the surface is going to give up its water faster than one lower down, but considering the water-holding capacity of the cubes, I’m not concerned it’ll be significant.

Just speculation...

One thing for sure - folks concerned about traveling and leaving their plants for a long time should definitely consider adding some rock wool to their potting media!

[WaterWitchin]

Originally Posted by Ray

...
Maybe in your current conditions it’s fine, but if your conditions changed to favor really fast evaporation, it might still outstrip the wicking, driving the “dry line” down.

Sure, a mini-reservoir closer to the surface is going to give up its water faster than one lower down, but considering the water-holding capacity of the cubes, I’m not concerned it’ll be significant.

Just speculation...

One thing for sure - folks concerned about traveling and leaving their plants for a long time should definitely consider adding some rock wool to their potting media!

For me, I'm already in the driest evaporation time of the year. The it-just-snowed have-furnace-on crap we call winter. Blech. So pretty sure I'm good.

I don't travel... too many dependent animals. But I would certainly agree on that one. Rock wool has been around for plant use since forever, but I've not seen in used much in the orchid world before, other than plugs for seedlings. It's used in aquatic plants a LOT; especially the ones grown non-hydroponically that sit in a bag on a shelf for months (like aquarium trade). I wonder why.

Here's speculation on that subject...I guess partially I was reacting to your "mix" of LECA/wool cubes on the previous page. To me that seems like way more wool that LECA... too much for my taste. Yes, lots of spaces in it, in a plain old dumped into pot. The issue I'm having is when repotting and incorporating those cubes into my mix. Just having it mixed in with LECA, no problem. But getting it in and around the roots of the growing plant, having to tap, poke, shake, prod with a chopstick to get it into the middle or down the sides. Especially with something Oncidium with the tremendous amount of fine roots. It gets too packed with rock wool compressing as I try to nudge it into place. That's why I just slowly drop in pieces here and there, and save the LECA for the tamping down part.