Orchid Board - Most Complete Orchid Forum on the web ! - Moss or other covering on top of LECA in s/h

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Moss or other covering on top of LECA in s/h

I saw some pictures that Underground posted and didn't want to hijack that thread so I'm asking here. My fan blows directly down onto most of my s/h plants and it's hard to keep moisture in the pot. Does having some spagh on top do a good job of keeping it in? And what are the drawbacks? I lean towards s/h because I have a bad habit of over watering and it solves the problem... Is there anything besides spagh that does well to hold in moisture but keep air moving? Thanks for any replies...

Well, i don't understand why you have a fan on it. I myself have a hard enough time keeping the sphag I put on top of the s/h moist without fans. I do find, that I mist the sphag in the morning, and it takes a few good hours to dry, so yes, I would say it helps quite a bit.
But still want to know why you use the fan. I don't find it necessary.

Without the added air flow I was having serious problems with mold and rot, even while using physan 20 and thiomyl. Due to space limitations having the fan on top pointed down was the only good option...

I don't like the idea, but only because it will 1) break down over time and 2) infiltrate the LECA, reducing air flow, both of which defeat some of the benefits of the culture technique. With sufficient diligence, one can use the moss and be pretty effective in managing the problems.

A side note - just because the top of the medium looks dry, it doesn't mean that it is throughout the particles, and the root systems will work their way down deeper anyway.

Tanner - any way to move that air horizontally?

Quote:

Originally Posted by Ray (Post 186797)

Thanks Ray.

I myself don't really use too much moss, just a light covering over the top. Probably why it dries so quickly. I use it mostly on newly planted orchids into s/h because I find that the plant really struggles with its first roots. The plant is willing to put them out, but its just too dry in my environment for those new roots to be successful. I have had plants that have tried and tried for months to root unsuccessfully. When I add the moss, it helps them out a bit.

rtsingleton, Your environment must be more humid than mine is, because I have never had mold problems with my s/h. :D Some suffer because of not enough humidity, others get too much, lol.

I remember that someone on the forum also had a problem with the top of the pot drying much quicker than the bottom. I think that person solved it by putting a layer of very small leca on top to help keep a bit more humidity. From what I remember it worked fairly well.

Humidity is the key. You're trying to balance the evaporation rate with the wicking rate of the medium. The fan pointed right at the pot makes evaporation outstrip the wicking.

I recommend against mixing medium sizes. Even if just used as a topping measure, the finer grade will infiltrate the rest, and that custs down the air flow.

I'll try to change air flow direction, humidity in the summer months when I'm not running a heater pretty much stays at 100% at night and at least 85% during the day... Thanks for all the help.