Reconsidering S/H
 

I am beginning to think I will give up on S/H. I read the success stories on here and wonder what I am doing wrong. I think it is a matter of moisture or lack of I must say. I see the pics with the nice moist pellets and wonder how you keep them that way. My pellets are always dry even with water in the reservoir and the few catts I have been brave enough to put just seem to dry up as well. My part of Texas is very low humidity most of the time, so I thought this would be a great way to grow. I need help. Thanks :scratchhead: :hmm

Ok. I should have read Ray's reply to an earlier post. Sorry:blushing: I guess my answer is water at least every other day. I was trying to get away from this.

Hi Linda,
I also live in a dry part of the world. The humidity during the day is around 20-30%.
I have been using s/h for 9 months and my phals & catts love it.
The point to the story is that s/h will not solve your humidity problem.
The humidity in my growing room is around 60%, I mist 2 times a day and sometimes more when the temp is above 100F.
I also grow my seedling in s/h, the humidity is kept at 75-80%.
My other suggestion is to flush with water everytime (or every other time) you fill up the reservoir, the phals seems to enjoy a soak in summer.
I hope that helps!:)

Linda, here's a couple of things to consider:

• Orchid-growing success is determined by your entire culture - air, water, light, temperature, humidity, air movement, nutrition, and your personal watering tendencies.
• "Semi-hydroponics" does not define the whole picture. It is merely an inert medium and watering method that simplifies the balancing of moisture and air flow to the roots.
• It is possible to grow orchids in almost anything, but you must pay attention to how all of those aspects interact.

If "drying out too fast" is a real issue, and you don't want to water more frequently, you really have no choice but to increase the humidity. If you go to more traditional culture, the potting medium will dry out just as fast, and if you formulate it so that it holds water longer, you will risk suffocating the roots.

Water retention in media has two aspects - the liquid that is absorbed by the components of the medium, and the droplets held in-between the particles by surface tension, bridging the air spaces. It is that "bridging water" that can suffocate the roots, so we try to keep it to a minimum.

Then, when you consider the liquid absorbed by the particles, you have to consider how well they release what they aborbed - and for orgainic components - how fast they decompose.

Many medium components absorb really well, but don't release the absorbed solutions as quickly, so surface evaporation outstrips the speed with which the liquid is fed out from the center of the particle, which leads to fairly rapid mineral buildup. The only way to improve that balance is to slow the evaporation rate, which means increasing the humidity.

Thanks guys. I tested my humidifier in the spare room I was talking about using. It works great in there. Nice moist air. This room is one of my spare bedrooms and only has a North facing window small window. Do you think that putting a table in there with my 8 growlights will suffice? Where I have my orchids now has nice big windows that are East/Southeast facing. I also have my growlights over my orchids in there. If I move, will it stress out my 'chids?

As the other location had more natural light, you might have to move the plants closer to the artificial light to compensate, but it ought to be fine.

Do you have a decent light meter? The kind of lights you select is not so much the issue as how much light you can provide your plants. I grow lots of mounted Angreacoids in a Wardian case in the basement which has zero natural light. I use a bank of 4ea 48" t5 florescents in a large fixture and the fixture is approx 10" above the high light plants like Dendrobium aberrans. I measure 1900+ foot candles. I also measure 750+ foot candles near the bottom of the tank where the shade lovers rest. That's approx 24". As Ray says, you may have to place lights close, but without a light meter, how do you know? If you go by trial and error, you may withhold light too much or provide too much. Let me know if you want recommendations on meters.

The humidity seems to be the killer. I tried switching over to S&H on a mix of 8 pap and phals in my office and now I'm down to 3 of the eight alive. Winter humidity in Minnesota appears to be just too much for S&H. I'd guess you need to get them established during a more humid time of year here. Anything already in bark has done well in the same conditions.

It may be more than just humidity itself.

In low RH conditions, there will be some evaporative cooling of the root zone, and that may be more of an issue, but one that can be overcome by warming things up.

If the losses occur not long after transplanting them, I'd pin it on the cooling delaying or slowing the growth of new roots.

I've been growing in bark with great success but I've been wanting to try S/H so I bought a bag of it on Sat. I don't want to have to water every day so I asked the supplier if people mix the s/h with other mediums and he said all the time. So I'm going to try using half s/h and half phal potting mix which is bark and charcoal for the most part. I think the s/h will provide really good drainage but the bark will soak up water and hold it there a little longer. Does this seem like a good idea? Maybe the original poster could try something like this too? I live in south florida where it's very humid most of the time, but if i grew up out west and I know how dry it can get. I might try mixing the s/h with sphag which might seem strange but perhaps you can get the moistness of the spag with the drainage of the s/h? just a suggestion.

Everyone has different growing conditions and there is no perfect medium. You just have to use what works for you.