Starting Catt seedlings in Hydro?

[Orchidenvy]

Originally Posted by Ray

I am not a fan of hydrophilic rock wool, as the texture is fine enough to be completely saturated with water, which means there can be no air flow within it. It's sphagnum to the extreme that doesn't dry as as fast.

When most folks talk about "hydroponic" orchids, they're referring to "semi-hydroponics" which is simply passive hydroponics and staying constantly moist. If they allow the LECA to dry out, it's really just traditional culture using an inert medium.

You are addressing exactly what I was wondering about! The rockwool I have does seem to dry to a reasonably moist environment after two to three days in the net pot (that is without any additional nutrient solution for wicking) I’m thinking that’s not going to be as convenient as the LECA/reservoir/wicking in a passive setup and possibly not as stable due to the unpredictable fluctuation from completely saturated to almost completely dry. As you noted the use of an inert media and wet dry cycle requiring a manual watering schedule of three days is really no different than using traditional (almost inert) media and harbors the additional risk due to the lowered oxygen exchange when at full saturation. I am however thinking if I see any drying beyond the top layer of LECA due to evaporation, rockwool May make a great topper as it would be expected to have a stronger wicking action due to greater surface contact with “wet” LECA. I anticipate that I will be repotting the rockwool plantlets to LECA shortly. I still am curious as to the possible benefits of a ebb and flow or deep water/oxygenated well/res setup.

---------- Post added at 01:21 AM ---------- Previous post was at 01:19 AM ----------

Originally Posted by Subrosa

I personally wouldn't grow most Cattleya any other way but semi-hydroponically. Even my nobilior which "require" a dry rest thrive in s/h. The only reason I used the word "most" is due to recently deflasking some Barkeria spectabilis. As I've watched them start to grow on I realized potting these plants in anything is a waste of time, as they'll just try to climb vertically right out of any pot. But other than that, s/h is the way to go for Cattleya under my conditions.

So, do you allow for a dry rest by emptying or not filling the reservoir?

[Subrosa]

Originally Posted by Orchidenvy

You are addressing exactly what I was wondering about! The rockwool I have does seem to dry to a reasonably moist environment after two to three days in the net pot (that is without any additional nutrient solution for wicking) I’m thinking that’s not going to be as convenient as the LECA/reservoir/wicking in a passive setup and possibly not as stable due to the unpredictable fluctuation from completely saturated to almost completely dry. As you noted the use of an inert media and wet dry cycle requiring a manual watering schedule of three days is really no different than using traditional (almost inert) media and harbors the additional risk due to the lowered oxygen exchange when at full saturation. I am however thinking if I see any drying beyond the top layer of LECA due to evaporation, rockwool May make a great topper as it would be expected to have a stronger wicking action due to greater surface contact with “wet” LECA. I anticipate that I will be repotting the rockwool plantlets to LECA shortly. I still am curious as to the possible benefits of a ebb and flow or deep water/oxygenated well/res setup.

---------- Post added at 01:21 AM ---------- Previous post was at 01:19 AM ----------



So, do you allow for a dry rest by emptying or not filling the reservoir?

Nope. I do withhold fertilizer, but water normally.