Why S/H isn't for me and now.

[YetAnotherOrchidNut]

I know a lot of folks on this forum use S/H very successfully. I am one of the people who tried it out and have decided, for now, that I wont be using S/H in my growing conditions, and I wanted to share my general thoughts about my experience.

I want to emphasize that I do NOT have anything *against* S/H. I have some modest experience of using various types of hyrdoponics, mostly active, producing extremely good results for other plants. From my point of view S/H is a just a form of passive hydro using leca (semi-hydro is a misnomer albeit good advertising), which is actually pretty similar to my preferred form of hydro, active-aerated-flow in leca. Only difference is in active flow you would have a reservoir with aerated water which you would flow through the leca using a pump. In the future, when I have a temperature controlled greenhouse I will try to grow orchids in active-flow, and in semi-hydro, but for now I will not.

I live in Amsterdam, and I have my plants on top of boxed in wall heaters in front of my windowsills in a no-AC house, and also in hanging pots. In my home the growing environment varies wildly in terms of day/night temperatures and available light (some of my plants are under lights as well). We peak out at over 16 hours of light in summer and less than 8 in winter. Winter is typical wet and for short period of the season will drop below zero. In the summer it can get up to 30c or more. So even if I set my house thermostat to not drop below 18c, the plants can see wildly varying conditions, at night dropping to 16c or lower near the window, except when the heaters turn on when they can go way up. Humidity in the summer can be high, and in the winter the heaters dry the air out, so it can drop very low.

Several years ago I became aware of the S/H movement, read all the articles, and put a bunch of plants into S/H, including an opportunity to take two keikis from the same plant and put one in bark and one S/H. At first the results seemed really good. It was spring going on summer when i did it and the results were positive, it seemed like the SH plants maybe grew a bit faster, except that contrary to what I expected it was more work to maintain my S/H plants than my non-S/H plants. I use the "long soak" method of watering my bark plants. I mix up fertilizer, fill up the cache pot, let it soak for quite a while, and then dump it. The comparable process for my S/H plants was "flush every time, and then empty and refill the reservoir with fertilized water". Which in practice for me took at least twice as long as what I would do with my bark plants.

But then winter came, and I noticed that the S/H plants werent as happy. In fact of the two keikis I potted the one in S/H rotted out and ultimately died. The others made it out of winter but were clearly behind the other plants. Some of my onicidiums rotted, and I had other issues.

Figuring I was doing something wrong I tweaked the setup a bit. Made new pots with the holes positioned a little differently, etc. I persevered with it for some time, but over time I observed that the phals i had left in bark had grown larger, produced more flowers, where the phals in S/H had dropped their lower leaves and were about the same leaf count after three years as when they started. I also noticed that the oncidiums I had not repotted were much happier. So earlier this year I repotted all my S/H in bark mixtures and after some time to adjust they have responded extremely positively, with massive root growth, new leaves, and etc. The Oncidiums in particular seem to really appreciate the difference and have clearly sped up their growth pattern and are producing much larger spikes.

I have been reflecting on why my experience was what it was, and I think there are two broad reasons, the first is that S/H gave me less options to respond to environmental changes, and the second is that bark is more tolerant of error.

When I say less options what I mean is that with S/H I had two options of media choice, a ball style LECA highly available, or a larger more irregular shaped LECA I could get from an orchid specialist. Other than that I could control the height and breadth of the pot, but I can do that with bark, and actually have more options to do so. With bark media on the other hand I have access to range of wood types and chip sizes, as well as a whole host of amendments like perlite, vermiculite, sphagnum, LECA, peat, etc. If I want to adjust the moisture levels a plant receives I can alter the mix. With S/H and leca there isn't much you can do beyond change the shape of the pot. Even watering more often doesn't really change things, once the reservoir is full its full.

The other thing is that its really easy to source tightly fitting cache pots for bark pots, especially ones where the inner pot "hangs" on the cache pot and does not actually touch the bottom of the cache pot. I found no convenient way to create the same effect with S/H. In fact a recurring problem I had with S/H was the reservoir draining accidentally if the cache pot it was within was moved, and I found no way to hand the S/H pot inside the cache pot. Eg, using S/H as a hanging pot is asking for trouble.

One theory i have about this is the way I mount my bark cache pots, and the use of the bark and other media combines to act as a stabilizing insulating layer around the plants roots that protects it from the colder nights and from the more extreme warm conditions when the heaters turn on. The fact that most of my plants "hang" in their cache pots means that there is an air gap between the inner pot and the media and the outside air. With my S/H plants I usually had them sitting inside of a slightly larger container, thus not creating a sealed environment in the cache pot like my bark pots have. Any temperature drop in the ambient air would be exposed to the entire surface area of the S/H container.

The second part is tolerance to error. My experience with hydroponics is that it is universally less tolerant to error. There are no buffers in the system which will provide some bounceback. For example, bark media as it decomposes turns acidic. Many water supplies are a little basic. Bark media will buffer the effects of the water. With hydroponics systems using LECA this doesn't happen. The fertilizer concentrations and ph levels in a hydroponics system can go through major swings over time just due to evaporation if not carefully monitored and managed. So if you forget to flush your S/H you are probably doing more damage than if you forget to flush your bark. For at least part of the time in question my lifestyle was inconsistent. If I had to go away for a few weeks I wouldn't necessary bother with my plants. This clearly to me affected my S/H plants more than my bark ones.

What I have found is that if you have a busy lifestyle, and cannot be very fastidious about PH adjustments, and fertilizer management, and cannot provide a stable environmental conditions, and in particular if you have to deal with cold weather fluctuation then S/H is going to be much harder to achieve the same results as you will with bark, especially if you have a lot of plants.

This is not an argument that S/H is wrong or that folks should not try S/H, or convert away. If it works for you and it makes you happy then I am happy for you! I fully believe that done properly under the right conditions SH is probably superior to bark. But if you have to grow plants in your living room in a northern environment and have a busy lifestyle then I think S/H is not what I would recommend.

Anyway, I just wanted to share a negative experience with S/H and my thoughts on why it was negative so folks in my situation can make their own decision.

[Ray]

From your post, it seems the only truly inherent issue with the use of s/h culture is your temperature minimum. The other issues appear to be “self inflicted” based upon your choice of containers and trying to apply your active hydro experience to the passive case.

In the simple, but effective, plastic container with an internal reservoir established by holes in the sidewall, every time you water, you “reset” the conditions in the pot back to where they are desired. Sure, because of biological action, that rhizosphere chemistry will cycle a bit (as it does in traditional culture), but the long-term changes are minimal, at worst. (Your assumption that media turning acidic is good because of high-pH water is not necessarily valid.)

As far as I am concerned, there is no “semi-hydro movement “, but there are a lot of folks that like to try new stuff without trying to understand what impact doing so might have. It is nothing more than an alternative culture technique. People who think it is a way to rescue plants are often fooling themselves.

[YetAnotherOrchidNut]

Originally Posted by Ray

From your post, it seems the only truly inherent issue with the use of s/h culture is your temperature minimum. The other issues appear to be “self inflicted” based upon your choice of containers and trying to apply your active hydro experience to the passive case.

Self inflicted vs difficult to control is a fine line. With S/H there are a small handful of parameters that you can control, width of the pot, height of pot, grade of leca, and count of the side-wall holes, and frequency of reservoir refill. With bark, I have basically all of those options, plus a whole bunch more which allow me to control the water retention and insulation policies to tailor to both the plants need and to my preferred watering schedule and time availability. I also get to make use of an entire industry of pots and cache pots to find ones /easily/ that produce good results.

FWIW, I don't get the comment about active hydro. I didn't treat it as active hydro, I tried as best as I could (modulo error and time availability) and followed the recommendations on your site for doing S/H. My references to active hydro were just to show that I don't have an anti-hydro agenda. I actually tried multiple different sized containers and converged on one that overall seemed better than the others, but it took some false starts. I found for my environment using a container more than twice as tall as it was wide, and keeping the drainholes quite low produced the best results.

The point was, even with hydroponics experience, and with a reasonable amount of houseplant and gardening experience the results I got from a comparable investment into S/H versus bark produced observably better results with the bark, at slightly lower efforts.

Also I don't feel like some of these issues are "self-inflicted". To me that sound a bit like blaming the victim. I /certainly/ don't get any say in the local weather, or the nature of the housing stock we have here. People grow plants in environments like mine all the time, and I am sharing my view that I think it is more difficult to optimize for these environments with S/H.

Originally Posted by Ray

In the simple, but effective, plastic container with an internal reservoir established by holes in the sidewall, every time you water, you “reset” the conditions in the pot back to where they are desired. ... (Your assumption that media turning acidic is good because of high-pH water is not necessarily valid.)

If you flush out the water completely and replace it with new formula then sure. If you top fill, or leave significant residue then I don't agree. Also I didn't say "bark turning acidic is good", I said it provides some buffer for harder water, and it was just an example of the way a complex bark with amendment mix provides various buffering and tolerance to error opportunities that I feel that a simpler pure LECA environment doesn't. LECA is great by the way, I use it as a bark amendment all the time and I definitely think my phals with it are happier than those without. I just think it works better with bark than by itself. :-)

Originally Posted by Ray

As far as I am concerned, there is no “semi-hydro movement “, but there are a lot of folks that like to try new stuff without trying to understand what impact doing so might have. It is nothing more than an alternative culture technique.

I regret that you found that term disrespectful. I didn't mean it that way. I see a definite "movement" and "counter-movement" with extreme positions on either side. I don't agree those on with those that say S/H is always better, and I don't agree with those that say S/H always worse. I am quite convinced that actually in the bigger picture hydro overall is likely able to achieve the best results. If you want to ultra-optimize your growing then some form of hydro is likely to produce the best results, but you need to have pretty much 100% control of every variable. I was quite happy with the ideas behind S/H. They make sense to me. I was disappointed it didn't work out as I had hoped in my current circumstances.

[WaterWitchin]

I'm one of those who grows exclusively in semi-hydro, other than mounts of course, because over the years it works much better for me than a bark-based medium. You indicated

What I have found is that if you have a busy lifestyle, and cannot be very fastidious about PH adjustments, and fertilizer management, and cannot provide a stable environmental conditions, and in particular if you have to deal with cold weather fluctuation then S/H is going to be much harder to achieve the same results as you will with bark, especially if you have a lot of plants.

I have a very busy lifestyle, have never adjusted pH, and my fertilizer management is at the far end of the scale of fastidious. It is much faster for me to water with SH than it was in bark. I can water everything at the same time, no exceptions. I have enough plants, 80-100, depending on whim. (When I reach 100, I cull down to around 80 and start the climb again.) I find semi-hydro to be much more tolerant, for me, for margin of error than a bark medium.

The fluctuation of temperature during the course of a year in Kansas is much lower and higher than Amsterdam's. Inside my house, in the orchid space where I now exclusively grow, my plants can see lows in the mid 50's F, up to 100F, depending on time of year. (No AC in that area in summer, supplemental heat in the area in winter.)

I think what Ray is saying about "self-infliction" by your growing methods in semi-hydro is another way of saying your culture in the method has not adjusted well to the requirements of culture for growing easily and well.

I've never done SH with a cache pot. Sounds tedious for sure. I have plants in SH that hang with no issue. When I decided to grow that way, I adjusted my culture to what works for growing in that method.

I have no qualms about folks who grow in bark, scoria, full water culture, etc. I just know it doesn't work well for me, in my particular cultural and care and environment.

[estación seca]

If temperatures are OK, and you completely fill the container to the rim at each watering, then allow it to empty, and do this frequently, it's very easy. This can be a lot of work in a home where you don't want to get water on the floor. I see people get into trouble when they avoid filling and emptying at each watering, in an attempt to reduce the work. I wouldn't have time to do it if I had my orchids in the house rather than in a sunroom where I don't mind water on the concrete floor.

[inga]

YetAnotherOrchidNut, I’m partially with you on this. I’ve been growing my orchids in s/h for 11 years now and some of them have declined. So I had to move to the bark all of my mini Angraecums, P. celebensis, Epidendrum stamfordianum to name a few. The others are thriving in s/h (cattleyas, dendrobiums, chysis). So I don’t know what’s a culprit in my case-the temperature or something else.

[Shadeflower]

hi inga, the Epidendrum stamfordianum is a warm to hot grower.
Warm to hot growers are more susceptible to suffering from cold feet in winter. Add to it it comes from a seasonally dry region. Orchids do vary. S/H is very "wet"
Cattleya hybrids are amongst my most adaptable, I find mini angraecums amongst my most challenging orchids.

Out of curiosity what mini angraecums do you have?

[inga]

Originally Posted by Shadeflower

hi inga, the Epidendrum stamfordianum is a warm to hot grower.
Warm to hot growers are more susceptible to suffering from cold feet in winter. Add to it it comes from a seasonally dry region. Orchids do vary. S/H is very "wet"
Cattleya hybrids are amongst my most adaptable, I find mini angraecums amongst my most challenging orchids.

Out of curiosity what mini angraecums do you have?

Hi, interesting, I was under impression once an orchid is in s/h we have to forget dry regions they come from and treat them equally by keeping them constantly wet. That’s the essence of s/h right? And if there’s a dry wet cycle then it’s no longer considered s/h. Correct me if I’m wrong.

Angraecums and aerangis that didn’t take to s/h are elephantinum, rutenbergianum, somalensis and mystacidii. However, A eburneum is thriving in s/h.

[Ray]

Originally Posted by inga

I’ve been growing my orchids in s/h for 11 years now and some of them have declined.

Have you repotted them into fresh medium in that time, or is it the original stuff?

If you have not replaced it, the general decline might be due to accumulated salts and wastes, leading to toxicity.

LECA may not decompose, but it does accumulate stuff over time.

[Dusty Ol' Man]

Originally Posted by Ray

Have you repotted them into fresh medium in that time, or is it the original stuff?

If you have not replaced it, the general decline might be due to accumulated salts and wastes, leading to toxicity.

LECA may not decompose, but it does accumulate stuff over time.

How long, on average, would you say is the life of the LECA?