New to semi-hydro - my experience so far
 

Hi all. I thought I'd share my experience of growing my orchids in S/H, lessons learned so far and how my orchids are doing. For us newbies to S/H it can be a very worrying time when we first start this method - from what I read, I expected my plants to instantly succumb to root rot and die! Apologies in advance for the long post.

I have 4 onc's and 2 dendrobiums (nobile-type) in S/H for over a month now.

I converted these to S/H after the bark they were in broke down rapidly this summer (only 3 months). The room they are in gets very hot in summer and cool in winter (converted attic). The water requirement of these orchids was very high in the heat and the fine bark I chose was breaking down from the watering and heat after only 3 months. I noticed there was also insects had somehow appeared in the media - obvious sign the bark needs changing. I decided that the watering needs were high so semi-hydro might be a good solution to help save time and prevent media breakdown.

This is my set up so far:
https://c2.staticflickr.com/6/5766/3...fced3341_m.jpg

The first oncidium is an intergeneric with 2 flower spikes from its pre-SH days. It is a Tahitian Dancer Pink Fairytale. The tag said Goodaleara but I heard its reclasssified as Aliceara. This orchid, from day 1, has been one of my best growers. It did get accordion pleating in the summer heat pre S/H but despite some issues with that, it has been such an easy orchid. It is perfect for a beginner like me - the bulbs stay plump and it produces roots rapidly. The new growth is not pleating in S/H (so far, so good!).

https://c6.staticflickr.com/6/5472/3...9d92bd1f_m.jpg

Looking at the roots, this orchid has not had any problems converting so far. The 3 new growths are also growing smoothly. However, I do have a residue - white powder - building up on the actual plant (possibly fertiliser but I have been using it quite diluted). This is a very fine-rooted oncidium but is doing very well. The only problem I faced in the conversion is that, while it has lots of roots, they always remain short on this orchid. It is almost just "sitting" on the LECA. However, it does not seem to mind.

https://c5.staticflickr.com/6/5823/3...0d458eb6_m.jpg

The next oncidium is a Sweet-sugar style yellow one. I bought it with zero roots. I never expected it to survive. It has severely wrinkled back bulbs from its days with no roots. I recently popped it into semi-hydro. It has some roots now and the new growth is magnificent in comparison - I am hoping it might even spike! It seems to like S/H and is holding its own. It is quite a mature bulb but is still producing some new roots so I went ahead and put it in.

https://c3.staticflickr.com/6/5580/3...61a502bdf2.jpg

The next two oncidiums are both intergeneric NoIDs, they are large and have thicker roots. Neither did very well for me in bark. This one fell apart during repotting into two sections. I decided I wanted them to stay together so they are potted back-to-back in S/H. Luckily both parts have new growth. I have never been able to keep these pseudobulbs plump. They looked equally terrible in bark so I will keep going.

https://c4.staticflickr.com/6/5449/3...055300ae_m.jpg

Another similar large-rooted oncidium similar to the Heaven Scent Onc's (it's a NoID), this one doing a bit better because it stayed intact. Some wrinkling but not much worse than when it first went S/H. New growth well on the way.

https://c7.staticflickr.com/6/5349/3...48269c02_m.jpg

The last two are my den's...

https://c2.staticflickr.com/6/5829/3...ff804a27_m.jpg

My Den's are both nobile hybrids and I partially regret moving them to S/H for three reasons.

First, I foolishly put them in S/H when there are no small new growths, the growths are already maturing :((. The canes are a bit short but I do not mind as they did remarkably well to grow as much as they did. I bought them flowering in mid-summer a bit out of season for them. I am hoping for better canes next year where I will push them harder with fertiliser next year.

Secondly, I had problems with staking. I did not want my bamboo stakes to rot in the reservoir so I had to improvise slightly by taping the stakes to the side of the pot......

https://c7.staticflickr.com/6/5734/3...8cde401c_m.jpg

The third reason I regret putting them S/H is that of the winter rest for these orchids that want to go dry. I am really not sure how to manage that in S/H. I know the options are to dry them out or keep the reservoir filled but no fertiliser. I do not fertilise these at the moment but do water as the canes are not quite finished. I have adapted my S/H for the den's by keeping the reservoir full for a week and then draining it and letting them dry a little bit (I have no prospect of new roots for a long time so need to be a bit careful). I also read a post from Ray that Den's tend not to do as well as other orchids in S/H.

My reservoirs stay full for quite a long time so it has been overall an easy way of maintaining these orchids. When spring and summer comes and temps go back up I'm hoping to see some good growth.

It remains to be seen whether I will continue my Den's in S/H. I am going to leave them for now with the currently treatment and perhaps put the S/H full force in spring, when the new growths start. If anyone else has grown these in S/H I would love some tips. I will be starting their dry rest when they finish their canes in the next few weeks. I plan to leave the reservoir empty. I am already seeing some leaves yellowing here and there so I am pleased that they seem to know they are getting ready for winter.

Let me know what you think of my set up and apologies for the long post. If you have any criticisms or ideas to improve their care I would love to hear your thoughts.

An excellent post. Let me make a few comments that may help you a bit.

1) Any plant can be grown in semi-hydroponics, but whether "you" (any individual) can do so depends far more upon their growing conditions and watering habits than it does the plant itself.

2) When you move a plant into S/H, the existing roots will likely fail, because they have grown to be optimized for the conditions they WERE in, so won't be optimal for the new conditions. That's why it's important to transplant into S/H right when new roots are emerging from the base of the plant, so they have the opportunity to grow and support the plant.

3) Referring back to my first comment, I have never said that dendrobiums don't do well in S/H culture. I have repeatedly stated that I cannot grow them that way. Others have told me they are ideal for the cultural method.

4) Nobile dens and other plants that require a "rest" are fine in S/H. You can either stop watering, as you would in traditional culture, or water it normally, but provide absolutely NO nutrition during the rest.

5) Your description of a "cold" winter concerns me. Most orchids like it reasonably warm, so if the air temperature is too cold, and the humidity is low, the evaporative cooling from the moist, open medium can lead to excessive chilling of the roots.

Thanks Ray! The room is cool in winter. It dips to 18C at night (64F) but is warmer during the day. I could move my plants but it would greatly reduce the sunlight they receive. The humidity is currently 67% with no additional measures to increase it. Where the UK suffers with a lack of sunlight it does have humdity - perhaps this will mitigate the evaporative cooling.

I will update the thread as time goes on to chronicle their progress. I will photograph any signs of improvement or deterioration. I am hoping for plump pseudobulbs one day!

I do worry about losing the roots. It is my biggest concern about the method. At least they are sympodial and have their backbulbs to lean on when times are hard. My yellow rootless oncidium really turned itself around by growing the new pseudobulb. It was once a little wafer sending out a new growth. The peculiar thing about this particular orchid is that, regardless of where it sits on the table, the LECA is always dry at the top. This is not the case for the others, the LECA wicks all the way and feels tacky and cool at the top. It also has a shiny look to it when moist but this one is dry at the top. Same LECA, same pot. I can't explain it, but it seems to be doing fine so I don't worry about it.

I have considered drying them for a day or so here and there just to make things a bit easier for them but I know that would not be correct S/H. I have not done this (except for the dens) but was considering it to slow down root loss while they get going...? Not sure about that.

My other thoughts regarding the dendrobiums: as semi-hydroponic roots will be replacing the existing roots. Would these new roots survive with an empty reservoir next year? I am keen to give them a dry-ish winter - as they will be relatively warm indoors. I have seen some literally covered in keikis. One or two is fine but on every node is too much!

Looks good.

Go to an Asian market and find some very inexpensive plastic chopsticks to use as stakes. They come in several lengths. You can leave those inside your containers.

Nobile type dens need very cool temperatures and withholding of fertilizer to bloom. No fertilizer after early August northern / February southern hemisphere. 18C / 64 F is not cool to them. They are hardy down to near-freezing. Cooler is better for flowering.

"If kept dry, these species and hybrids will survive winter temperatures of 37-39 F (3-4 C) and will flower around April."

I really don't understand why folks shy away from constantly wet roots, if it's done right. Many orchids experience that in nature, and if that was problematic, they'd be extinct.

Update
 

I wanted to update my S/H experience thread. I still have my 4 oncidiums in semi-hydro and my 2 dendrobium nobiles. I think it is nice to have a diary of the process and help others decide if this is what they want to do or not.

First up, the Aliceara Tahitian Dancer - with the dual flower spikes.

The flower spikes are painfully slow to develop but we are getting somewhere! Bulbs stayed nice and full. This is the one that "sits" on the LECA as it has lots of short little roots.

https://c4.staticflickr.com/1/88/315...bab68fde_m.jpg


This orchid, as I said earlier, is so forgiving. I have disturbed it so many times and it doesn't shrivel. It loves water and gets accordion pleating if it doesn't get it. The new growth looks smooth. You can see the pleating on the summer's growth a bit better here:

https://c5.staticflickr.com/1/485/31...806e83bc_m.jpg

Here, I move some LECA aside to take a peek at the roots. This plant is tolerating the S/H and I am fairly pleased with the roots under the LECA.

https://c5.staticflickr.com/6/5532/3...684f510b_m.jpg

Another side:

https://c2.staticflickr.com/1/207/30...8b5fac63_m.jpg

Overall, this plant seems to love S/H and I will be keeping it as it is for the longer term.


Oncidium dancing lady (yellow generic one)

This is the one that was rootless when I got it and produced a new bulb. Old bulbs wrinkly due to being unable to take up any water. The new bulb looks great and has started a new growth since I started the thread last month. It has decided not to bloom at the moment. I am not disappointed. Instead, I am grateful that it is still alive because I didn't think it would make it.

I thought it might not take as well to S/H as the bulb was quite mature when moved over and ideally I would have done it sooner. I have since put this oncidium under CFL lights to give it a bit of a boost this winter.

https://c5.staticflickr.com/1/657/31...108c50f5_n.jpg

I am very optimistic about this plant as the new growth will bring new roots that will help it adapt to S/H!

Let's look at the roots...

https://c8.staticflickr.com/1/135/31...e2b0c737_n.jpg

The root at the front is really gripping the LECA bead and looks great. A few roots look a little "dark" but I think this is a little bit of algae not rot. I am seeing some branches coming from them so I think they are OK for now (I might lose them at some stage though). The bulb is still sending a new root down as you can see.

I am very pleased to see this older root doing well.

https://c8.staticflickr.com/1/553/30...daa9894b_m.jpg

This plant is harder to gauge because it had so few roots to begin with. The few roots it did have were strong and recent and the plant seems to be tolerating semi-hydro. I am going to continue.

Now, my two larger rooted oncidiums with the big roots.

The first is a Colmanara hybrid. This fell apart into two pieces (potted together) each with a new growth, so it's doing its best.

They were potted into S/H at an appropriate time and I am pleased to see new roots forming.

https://c5.staticflickr.com/1/321/31...6040c03b_m.jpg

However, you can see there was some root loss:

https://c2.staticflickr.com/1/721/31...5678a036_m.jpg

The other NoID oncidium is similar. I feel it has plumped up slightly but I am never sure so I like to photograph them.

https://c3.staticflickr.com/1/329/31...95b2d471_m.jpg

Roots - again a bit of a mixed situation but the new roots are keeping me optimistic about things.

https://c4.staticflickr.com/1/151/30...df7611a1_m.jpg

I will keep all four in semi-hydro in the longer term.


Dendrobium nobile hybrids


https://c1.staticflickr.com/1/535/30...ee28e989_m.jpg

This isn't really semi-hydro (yet). I have them in LECA with an empty reservoir. I have just been spraying the roots and the leca here and there when looking very dry. I plan to do the full conversion in spring.

Overall, I feel none of my oncidiums are struggling in this method and I would like to convert more orchids in spring. I am tempted to dabble with phals in semi-hydroponics but I am slightly intimidated - sympodials are much more predictable in terms of growth patterns and when to expect new roots. I do not have an eye for when a phal should be converted.

I have since moved a cattleya and a phal into LECA with a traditional watering system. I love the media. It absorbs enough water but is also airy. It is perfect in my conditions. It dries more evenly than bark and is inert.

I am encouraged by the results so far. I am not complaining about any root loss. I expected it and I am just documenting to what extent it has occurred. I am pleasantly surprised it is not worse.

It has remained a really easy way to maintain my plants and I have enjoyed it. Watering is easy, especially for thirsty oncidiums. I also find it quite fun to flush the pots. I have not really got algae around the pots but it may come.

I had a mild "fungus gnat scare" where I saw a few adults (not many). They seem to be gone now though. I have not seen anything for weeks. I have been poking around trying to find larvae/adults and I haven't found anything. They seemed to be attracted to the S/H water but luckily the inert media came through for me - otherwise I'm sure I'd have a problem on my hands with organic media!

Expanding semi-hydro collection
 

I've decided to add more orchids to my semi-hydroponic experiments. I am very pleased with the method so far and would like to see how other orchids react.

Bifoliate Cattleya
This bifoliate cattleya is just some rootless backbulbs that I am trying to propagate into a new plant. One growth is rooting and it has another little growth appearing so I felt it might be fun to see how it does. I have lots of copies of this plant that I bought to use as practice plants (I got them on clearance).

https://c4.staticflickr.com/1/531/31...8997a027_n.jpg

This is the parent plant in bloom. It has a lovely fragrance. I enjoy growing cattleyas so much. They are so resilient that I'm sure things will be OK.

https://c3.staticflickr.com/1/567/31...3e498484_n.jpg


Phalaenopsis
I mentioned earlier my uncertainty about phals. This is because I find them... well... let's just say I find them difficult to grow. They do spike but the root systems leave a lot to be desired. I am interested to see their reaction to S/H. I was hoping to wait until spring/warmer temperatures, but there was just so much root rot going on that it couldn't wait.

https://c5.staticflickr.com/1/270/31...a59af8a8_n.jpg

- The photo above makes it look like the pot is huge but it isn't - I just need to gently wiggle it more to the middle when I flush it. The roots are not as good as they seem in the photo - there is little below the media.

https://c7.staticflickr.com/1/466/31...a47163f7_n.jpg

Both are spiking. I will probably leave the spikes alone for now and see what happens. I hope it is not too gruesome when the old roots die away as they're so thick and fleshy.

My experience has been that Phals take to S/H well and almost instantly. Keep them warm.

Estacion Seca and Ray... I think you both gave me a light bulb moment about all this root rot in my phals. They must need more warmth. No wonder they are all spiking like crazy. I don't know why I didn't connect the two sooner. Luckily in summer it gets nice and warm. So...

I've turned up the thermostat and positioned the phals closer to the radiator with my temperature monitor next to them so they stay warm. Humidity is OK. I've also got a seaweed product to spray on them and add to their reservoirs when I next flush. It isn't Kelpmax but it seems like a similar product. I found it when I went orchid shopping today...

Stupid phals. I have had a few that just die when I take them home. I have this one I tried to kill one summer 3 years ago. Well it has recovered thanks to S/H and I have a spike. I fell your pain on the lack of roots on phal I think my home is just too cold for them too.

I have been growing in SH for almost a year now. I like it it's easy and clean. I still have a few in bark mix. With orchids nothing comes fast. It takes time. With time SH works great.

Hi everyone. I just wanted to update my experience thread.

I have had good results with oncidiums, including the once rootless and pitiful yellow dancing lady oncidium. The new growth is well on the way.

https://c1.staticflickr.com/1/514/32...f67d7d18_n.jpg

Roots look happy and it feels sturdy in the LECA now - which doesn't really move around like it used to. There are roots skimming the top and also roots going down into the LECA. They know what to do and the tips don't dry out or anything.

https://c1.staticflickr.com/1/640/32...b5649182_n.jpg

I have also had success with the Cattleya. Standard cattleya advice is to allow the dry period, however, they seem to have a high amount of adaptability with the new water roots. This is the update on my back division. You can see one root poking out halfway down.

https://c1.staticflickr.com/1/438/32...4b9e9c21_n.jpg

There is also another root growing here and they look like they are holding their own in the wet environment and I'm looking forward to seeing how it reacts to the reservoir. However, I would say old roots can die very quickly so I wouldn't keep any root that is questionable or broken (I find old cattleya roots pretty temperamental in general).

https://c1.staticflickr.com/1/612/31...2c5f4a14_n.jpg

I have also put a Brassia, several more phals and 2 further cattleyas into it but I won't post pictures as there is not much happening.

For sympodials, this method has been a huge success as they produce all their roots in one big flush and it's easy to predict and time the transfer. I am struggling with my phals though, they are going limp and dropping leaves. I'm keeping them warm but I think the switch from just bark on its own to S/H has been a shock for them. I intend to give them another 3 months and see if things pick up.

Does everyone else manage their algae or do you just leave it? I am starting to get some but it doesn't bother me hugely.

One thing that jumps out is that the plants appear to be potted too deeply. You want the bases of the plants right at the medium surface, not below it.

At this point, you may safely grasp the plant, and while jostling the pot a bit, pull up gently on the plants to the proper position.

You may find that the plants will be a bit wobbly (precisely why most folks plant too deeply), so stake the plants until they "lock in" with their root system.

Oops. After my repotting sessions I think I have been mindlessly scattering leftover washed clay pellets into the other pots rather than putting them back in the bag. I will remove a layer or lift plants where possible. Thanks for pointing this out.

With the phals, is it worth putting a plastic bag over the sick ones to buy them some time? I don't want to invite mould or rot but I would like to try to help. There are 8 phals currently in S/H including a few rootless ones with nothing to lose. If I lose any plants I will specify whether they were rescues or converted properly. However, I am interested to see if S/H can assist in recovering a phalaenopsis in this state by providing a continually moist and humid environment as it seems water culture can.

Hi FlowerPower. I´ve really enjoyed reading through your posts. I used to live in England, where I only ever tried one orchid, and that died. I lived in Brazil for years, and had loads of orchids in my trees, very easy. Now I´m in Portugal, and it´s more of a challenge. I´ve been thinking about s/h for my orchids, but decided against, due to the possibility of chilling the roots on the leca, so then I was playing with the idea of fwc, (the roots dry very quickly here, swc isn´t enough, nor is mounting which I also tried). But now I think I will try s/h after reading about your success so far. Thanks. And thanks to Ray and Estación Seca, too, for extra explanations.

Hi flowerpower,
Enjoyed reading your thread.

I live in a similar cool, wet wintery climate as you and have transferred the majority of my plants to semi-hydro and gone through winter with great success (oh boy, it's hard to write that for fear of jinxing myself).

I have phals (including very warm growers like bellina), phrags, paphs (from multi-floral to parvi), oncidiums, angraecums all in semi. They have all grown the loveliest roots and it's such a pleasure to see them dipping and growing down into the water reservoir. One of my phals has roots growing in a circle around the bottom of its reservoir.

I was nervous, too, about repotting them in semi, but all the plants have done so well, I only have a handful not in the media. I read all Ray's articles on the subject at his website firstrays.com and followed his instructions (sometimes to the 't', sometimes not [some plants went directly under lights without a dark period because they were in active growth]). All were started on heat mats, which is something I'd like to recommend to you. I think heat mats in your winter environment would be very beneficial and would speed up new roots growing. It keeps the reservoir water warm and seems to trick the plant into thinking it's spring and time to put out new roots.

One thing I've also done is add lava rock to the top of the LECA. The LECA I can get is always different and some of it floats like crazy (which makes watering a pain). The heavier lava rock helps hold the LECA and the plant in place (quite often so well that skewers are not necessary) and allows new roots to grow without the plant wobbling around in the media.

Good luck!

Flowerpower where did you buy your leca from? I'm in the UK too and haven't seen it anywhere.

I got it from a hydroponics store, it's very cheap and they always have it in stock. Hydroponics stores are also a good source of hydrogen peroxide for disinfecting roots. The brand I used is called Canna.

Thank you so much for taking the time to share you experience with so much details and pictures.

I'm new the Orchids world. I only have two NOID Phal and a Wilsonara Kolibri that I just got when I visited an Orchids nursery last week.

Before, I got my Wilsonara I had read about S/H and I felt I wanted to start with this type of culture for the sympodial orchids. I actually bought it not flowering and growing a new bulb just to try this. (I'll buy flowering Orchids when I go at the Montreal expo this week-end, Phal and hybrids from the Oncidium alliance.)

But when I got home I kind of got to scared to experiment with the S/H and changed my mind. But your post got me back on track I should try this with my Wilsonara.

Most of what I read so far about S/H was on French web site. Is there a specific " How to do S/H " here that you know of ?

Thanks again :waving

The best and most detailed exposition of semi-hydroponic culture is on the First Rays Web site.

All of my oncidiums seemed fine in semi-hydro if timed with the start of the new growth so it seems fairly safe. I also found cattleya divisions with few roots a good choice.

I removed my phals from semi hydro as I did not like the direction things were headed. They can be converted to semi hydro but I couldn't adapt mine. The new roots stopped growing when they touched the leca so they're just little stumps while the old roots died - leaving me with nothing to support the plants. I prefer water culture or sphagnum moss for phals but I just chalk it up to experience.

My dendrobium nobiles are growing in semi water culture now too and they seem to really like it. They are very easy-going so probably would have been fine in semi-hydro - but I could not get them to stay upright in LECA as they're very top-heavy!

Hi there I know your post is from some time ago, just wandered if you still doing ok with SH with your orchids. I am also in UK and wished trying SH or water culture. Have you got any in full water if so how is it going. Thank you very much in advance.

I have been trying again with converting my phalaenopsis into semi-hydro during the warm summer and had much better results than I did moving them during winter. Phals are the only ones that I found tricky but if they have nice healthy roots then they seem to do a lot better.

I have done full water culture in the past and it does work but washing the vases is a pain. I dislike the murky water. Also, I think orchids benefit from attaching/securing themselves to their growing media so I prefer semi hydro.

Thank you so much for replay. Well have to wait until summer then to try it out :)
It is nice to compare growing with people living in the same enviroment as your self.

You may find it easier to convert phals in the summer, because of the temperature, but I'd still be wary of doing so if the winter temperatures in your growing environment cannot be called "quite warm."

For the most part, phalaenopsis are warm- to hot growers that can tolerate our preferred temperatures reasonably well. However, if they are exposed to cooler temperatures with damp roots, they will suffer, and if the combination of lowered thermostats and dry air leads to evaporative cooling, pushing the temp even lower, the roots can die.

I have moved my phals out of the original room they were in, which is hot in summer but cold in the winter. The rest of the house is consistent in temperature except that room (it's a converted attic bedroom).

I had such consistently good results on more intermediate types like cattleya/oncidiums that I was a little complacent with my phals. I will see how it goes this winter and will focus on warmth and good light. I have a new LED that I keep in a spare bedroom away from the windowsill that they might enjoy. From observing my phals, I think part of the problem was the poor timing as well.

Even though they came close, none of my phals died. The new leaves emerged small due to their poor health but they have new root systems now and the leaves are growing bigger. A few are blooming away.

I have placed a paph and a few other oncidiums/miltoniopsis/cattleyas into S/H so I look forward to sharing my results. My paph seems fine after a few months. I do have a cattleya that was rootless for almost a year. It was doing nothing. It started to root quite soon after placing in S/H. It seemed to sense something....

Hi Ray thanks for your replay. I might leave phals where they are as I am doing real well with them in bark and seramis mix, some are in Leca and seramis but not SH and they also are healthy. It is oncidiums and cattleyas that I am thinking of moving to SH, but will listen to you guys and wait until spring.

The wait should not be based upon season, but upon the emergence of new roots from the base of the plant.

That often IS seasonal, but not always, and the issue can be forced with prudent use of plant growth stimulants.

Updates
 

I've been a bit quiet on the S/H updates lately. This is because I was trying new orchids and gathering more experience with my existing orchids (especially recovering my phals). I have a renewed interest in S/H and have converted more orchids.

I want to start by discussing old mistakes and add some new experimental S/H candidates!

First, let me update the phals. Good news this time!

A year ago, I converted my phals to S/H in a cool climate at a low light time of the year (autumn/winter time). This was a big mistake and although they all survived, they did lose all their roots. They are getting healthier though and the leaves are now growing to a more reasonable size. Last year, I was continually experimenting on them, repotting them and disturbing them until I ended up in a downward spiral of root loss. I recovered them for a few months in sphagnum and tried again. I converted much healthier orchids with nice, healthy and INTACT roots. I suggest putting a phal like mine with messed up roots into moss so it can grow some nicer roots before attempting conversion - as there is no pseudobulbs and some nice roots deep in the LECA beads will help a LOT. Otherwise, everything dies and you just have a dehydrated mess on your hands. I currently have 18 phals growing in semi hydro but I have to say they have been my most challenging conversion.

https://farm5.staticflickr.com/4558/...7c1cf0b1_n.jpg

The next phal was completely rootless last winter, it lost about 8 leaves. It's now happy in semi hydro, LOL. It has bloomed, despite having very small new leaves they are getting better.

https://farm5.staticflickr.com/4524/...25141fea_n.jpg

https://farm5.staticflickr.com/4483/...7878a842_n.jpg


Now, issues:

Root tips. The roots above the LECA don't dig down very well into the media.

Unexplained root tip death:

https://farm5.staticflickr.com/4463/...df673b5a_n.jpg

Shrinking, dying root tip:

https://farm5.staticflickr.com/4490/...5cbd875c_n.jpg

I am genuinely afraid for these root tips as I don't know what to do to help them except mist them when I have time. I love how they curl around in the deeper layers but the surface roots do not do well for me and was part of the reason I had so many troubles last year - even the phals with new roots were left with just a few short stumps above the media!

https://farm5.staticflickr.com/4525/...df9ef13d_n.jpg


The next orchids:

Cattleya seedlings!

I love these! These are both RLC Liu's Joyance

https://farm5.staticflickr.com/4541/...96552eda_n.jpg

They arrived in a coconut shell and were pretty mangled when I freed them. As you know, cattleyas are a bit funny about their roots and they didn't really have anything very good on transferring over. They were masquerading as a single orchid but once freed from their coconut prison, it was two extra small ones together. They immediately took off in semi hydro without any issues.

Roots:

https://farm5.staticflickr.com/4510/...21f94756aa.jpg

These are all new and I don't know if the photos actually show how small these seedlings are.

Another cattleya seedling: BLC Nakornchaisri delight. Again, trapped in a rotting coconut.

https://farm5.staticflickr.com/4455/...5b8a1798_n.jpg

As you can see, there are no weird root tip death issues here and I have not experienced this at all in the cattleya alliance. It looks a bit lopsided but that is just how it grows and it is very secure in the media (I could probably lift the whole thing by the orchid but it's a delicate seedling so I won't!).

Roots:

https://farm5.staticflickr.com/4479/...087dfcaf_n.jpg

As you can see, I do not manage my algae very well. I just ignore it for the most part. The roots are hard to see but they're alive and doing well.

Cattleyas show a huge amount of adaptability in their old VS new roots. Where the old roots are completely unable to cope in the new medium and the new roots are completely different and actually thrive in constant wet conditions. With phals, however, sometimes if you have a good, healthy, growing root you don't always lose it. If it's old and broken up/cut etc it will have quite a low probability of survival.

I have plenty of other orchids to discuss!!!

My future posts will cover vandaceous, adult cattleyas, den phals, den nobiles, paphiopedilums, miltoniopsis and more on oncidium intergenerics (if you haven't had enough of those yet!). I have my first catasetum-type (cycnodes wine delight) which may end up in S/H.

As you can see, I have been orchid shopping this year!!!

Happy growing to all and I hope your orchids are thriving, however you decided to grow them!!!

Good work. I suspect the Phal root loss is due to insufficient watering, or those were old roots that didn't adapt.

If the water doesn't wick up far enough to keep the top of the LECA moist roots up there will die unless you water fairly often.

Two comments:

For phalaenopsis, I recommend a much broader, and likely shallower pot. Do not be afraid of "overpotting" with S/H culture; the LECA spreads the moisture far more evenly, so there's no "soppy center". Plus, aerial roots will tend to enter the pot that way, making it more stable.

The root-tip death is due to desiccation. LECA is VERY absorbent, so if a root tip comes in contact with a dry pellet, they will extract the moisture from it. A shallower pot, more frequent watering, or even better, raising the humidity in the growing area, can alleviate that.

I have a couple of questions. This will be my first winter in semi hydro. I keep my "warm growers" in a room that right now ranges between 28°C during the hottest hour of the day and 20°C at night (82°F - 68°F). It's still really warm in Mexico City. I glued one of those cheap aquarium thermometer stickers to one container and the temperature inside hasn't dropped from 20°C. So my question is, when should I fire up the heat mats? And will it affect the blooming cycle?

To answer that, one has to consider two aspects:

1) Is the plant's blooming affected by temperature? Of typically-grown orchids, phalaenopsis are the most common in which that answer is "yes". But if it has already seen the required period of average temperature reduction, heat mats are no issue, and may actually help the growth and blooming.

2) How is "warm-growing" defined? Many cattleyas, for example, are warm-growing, but have no issues with a moderate chill. Phalaenopsis, on the other hand, are actually more "hot-growers" than "warm", but are pretty tolerant of warm conditions. They will not do well with chilled, wet roots.

My growing area has winter temperatures like yours in the day, and cooler at night. I don't use a heat mat. My Phals do fine.

Do you think a good spraying with water onto the root and surface of the LECA will assist in getting the roots past the upper layer? I have natural humidity and my dry line is only 1-2 layers down.

I was thinking of making a little hole by moving the beads around and letting the root go down before covering it over again?

Does the dry line affect some orchids more than others? My cattleyas are not bothered at all and neither are my oncidiums. Hopefully the den-phals will be OK, it's my first time growing these.

I think the issue with spraying is the need to do so very often, to keep it moist.

You might consider a plastic cover or film "tent" over the top of the roots and the pot.

One decent idea I've seen was to make a round, clear plastic "cover" out of a vinyl page protector sold at Staples and the like. Make the disk be about 1" smaller in diameter than the pot, cut it radially to the center, and remove a portion in the center, about an inch bigger than the base of the plant. The gaps allow you to water with it in place, and it still allows air flow, but some of the evaporating water will condense on the plastic and drip back into the pot.

Hello,

I’m glad to see you kept up-dating this post. It is very interesting. I intend to get Cattleya and grow them in SH.

I wrote in March, to tell you, that your post gave me the little push I needed to start the SH with Cyrtocidium (Wilsonara) kolibri.

http://www.orchidboard.com/community/836927-post19.html

At the time I got the Kolibri, the roots were in a bad shape, they were pretty much all rotten. Any how, it is doing pretty good now. The pseudobulb even plumped.

I also decided to grow in SH, a Schunkeara (Beallara), a Miltoniopsis and a other Oncidium (Odontoglossum type one), that I got shortly after, and they are all doing pretty good.

Only two of them have algae and they are the ones for which my wather reservoir are glasse one. The two other one are white opal reservoirs. I was told that algae need light to form. Maybe that algae will eventually form with time. However, it does not really bother me but it would be nice to avoid it.

Any time there. Is a combination of light, water, and fertilizer, there will be algae, but it really does no harm.

Once it has appeared, you don't want to kill it in place; it's bettering to repot and then clean the old one. Preventing it in the first place is the key.

For folks using clear or translucent pots, I used to recommend a monthly watering with a disinfectant like Physan, but I have since learned that algae growth is very often an indicator of over-fertilization.

When I reduced my feeding from 125-, to 25-35 ppm N at every watering, I no longer had an algae issue, and my plants actually grew and bloomed better than ever.

I used to worry about algae and what would happen when it builds up a lot. But it looks a lot worse than it really is. It's confined to the inside of the pot walls and I've learned to co-exist with it and ignore it.

I was going to try the pot covers that Ray suggested but I decided I will first try increasing my frequency of waterings to address the dry root tips. Rather than waiting for the reservoir to go down and misting the top, I will just water those ones perhaps 2 or even 3 times a week until the roots go down. I enjoy watering my orchids so this should not be a problem and they seem to respond well to frequent flushings. Unless that is just my imagination! I won't be fertilising them every time though. I will probably alternate fertilier and plain water so that I am not wasting it. Especially on orchids that are not quite fully established.

As for updates, vanda seedlings are not doing much, cattleya seedlings are going nuts. Oncidiums looking plump and miltoniopsis leaves growing smoothly and reasonably quickly. Paphiopedilums are alive and just plodding along - no signs of distress but really difficult to gauge what's really happening in the container. Phals are doing fine with the cooler and dim weather in the UK. We are getting near to freezing at night outdoors, though of course they live inside with central heating. I'm not out of the woods but they look a lot better than they did last year.

I'm very much looking forward to my new den phals to get established so that they are able to support themselves a bit better.

I was watering my orchids today and enjoying that I can water everything all at the same time. I was struck by how healthy everything is looking. I recently threw some IKEA den phals into semi hydro and they seem to be doing well.

Many of my orchids including cattleyas, phals and oncidiums have roots down to the reservoir with no apparent issues. It is nice to know the LECA does not break down and I won't have lots of repotting to do this spring. The only orchid for me that did not like semi hydro were vanda seedlings and TBH I expected them to hate it (but I wanted to see how it would go as an experiment).

My phals are doing great in semi hydro, no issues with it being winter/cooler but I did the conversions at a warm time of the year so they could settle in before the winter came. Only 4 out of my 20 phals did not spike yet this season but they are in the lower light window so I think they will bloom in spring.

I only have one big cattleya in bark that I am afraid to disturb and one phal left in moss. I have around 50 or so orchids in S/H and could not be happier with the technique. My paphs seem totally unaffected by the transfer to semi hydro.

The only orchids that I grow routinely in bark now are the cymbidiums which I keep in the garden year-round. The cymbidiums are so big that I am happy just to carry on with Orchiata for these.