Newbie converting from lava / bark to SH.

[daddydoall]

This S/H method seems like a good idea, never to wet, never to dry?? I have had mostly good luck using lava / bark combination, but have some plants being too dry hot summer, and others too wet in winter. I am not interested in setting up a complicated system.

1. Can I simply use expanded clay product in pots sitting in a shallow tray and flush / replace the water / nutrients periodically?
2. Should I use taller pots, I like to use shallow clay ones? 3. Should the trays be removed in the winter when weekly watering seems to be sufficient anyway.
4. I use bottom heat in winter on part of collection (if ambient drops below 50F), so having a water tray would help store heat, but I'm concerned with it being too wet in cold conditions (40-60F) when heat is not on.

[mtorchid]

What kind of "pots" are you referring to? S/H method requires a pot that holds a reservoir of water at the bottom, wicking the moisture upwards through the roots as it evaporates. You can use the clay pellets as a traditional medium in a traditional orchid pot but you would be watering more often from the top down. Even if you did that, you wouldn't have to worry about the medium breaking down like bark.

Whatever local humidity/heat control you're using now would also work with clay pellets.

[daddydoall]

i was wondering if a shallow tray would work just as well with traditional clay pot??

[desertanimal]

It will work, but I think your issue there is the possibility of disease transmission. It also seems a bit more complicated to make sure you're flushing all pots from the top down in such a set-up. You want to flush a whole pot's worth of water through each time you water to make sure you flush out the dissolved solids that precipitate as the water evaporates. But if you flushed all pots and didn't care about the risks of a shared reservoir, it would work the same.

[ALToronto]

Use plastic or glass pots, and drill a single hole about 25 mm up from the inside bottom. To flush, plug the hole with any finger except your thumb, fill the pot to the top with water, then move the finger to open the hole and let the water drain out. If you use your thumb, you will be wearing it.

I use a combination of clay pellets and lava rock for s/h, I find clay pellets alone to be too lightweight.

[Ray]

Individual plant trays certainly can be used with regular plastic pots; it'll just be an external-, rather than internal reservoir. Don't do that with clay pots unless you're growing high-altitude species that prefer it cool, as a lot of evaporative cooling will occur.

I disagree with Alla's recommendations.

1. If you only have one hole, it is possible fora LECA pellet to mostly block it, making flusing difficult to accomplish. If there are two 1/4" holes right next to each other (as close as possible without intersecting), even if that happens, that pellet will prevent the other hole from being blocked.
2. For flushing, if you close the holes and fill the pot, you'll be spreading the questionable chemistry of the reservoir throughout the medium, where it can be absorbed. if, on the other hand, the holes are open, that will mostly be pushed out as you water, giving you an overall "fresher" chemistry throughout.

[daddydoall]

I transferred much of my Cat collection to a variety of SH pots to see what works best in my environment. Contrary to Ray's experience with Cats doing this in the winter (40-50 F) was a bad idea as several young plants rotted even though the reservoir-basin was only intermittently filled. I have put them all on a heat mat hoping to rescue and removed the reservoirs. Plants need to adapt to new media / cultures and doing this in active growth is likely better.

[mtorchid]

Originally Posted by daddydoall

doing this in the winter (40-50 F) was a bad idea

Are those the ambient night temps? That's way too cool for Catts and there wouldn't be much evaporation from the LECA either at those temps. Yes, active-growth period is the best time to repot so new roots adjust to their new environment but at those temps I suspect you would have the same results.

[Ray]

Originally Posted by daddydoall

I transferred much of my Cat collection to a variety of SH pots to see what works best in my environment. Contrary to Ray's experience with Cats doing this in the winter (40-50 F) was a bad idea as several young plants rotted even though the reservoir-basin was only intermittently filled. I have put them all on a heat mat hoping to rescue and removed the reservoirs. Plants need to adapt to new media / cultures and doing this in active growth is likely better.

I think you must have misread something. I don't recall recommending transplanting anything in those temperatures, and always recommend - especially with plants like catts - that they be replanted when new root tips are just emerging from the bases of new growths.

I have transplanted cattleyas into S/H in winter, but only if that latter new growth is present and I am capable of keeping them much warmer than that.

[daddydoall]

Should of waited to spring!