Worry-free orchid setup

[spujr]

Hi,

I've been playing around with a growing setup that would be entirely (well, mostly) automated on watering.

The idea of this setup is the fans on top would blow air up, thus pulling air down through the LECA containers for rapid drying and good airflow on the roots. When the moisture sensor reaches below a certain point the pump will turn on and re-flood the chamber. Humidity goes back up and pump turns off and the water drains back down.

Pictures below. I already identified some faults of the system, some are obvious:
1. One water source could easily spread disease among plants.
2. The LECA floats when the chamber floods which sometimes causes the humidity sensor to fall out and thus the pump will run continuously. Not a huge deal because there is a overflow feed back to the pump but plants could drown. Floating LECA might also uproot plants too but so far hasn't been an issue.
3. The quick evaporation reduces temperatures. Warm loving plants might have problems especially in the winter.
4. In general the setup takes a large footprint. Like bringing a gun to a knife fight.
5. The humidity sensor that I have either doesn't work well or not sensitive enough. Might buy something else or just go with a static timer.

Anyways, far from perfect but just having fun experimenting. Thought I would share in case someone had ideas for improvements.

 

[Ozpaph]

why not just drip water the leca on a timer?

 

[spujr]

Good idea, certainly could work, I would just need to get some tubing and spaghetti drip lines but essentially the same concept.

 

[Ray]

Rapid drying of the LECA will lead to rapid mineral buildup. In my experience, that is unnecessary and I’ll-advised, and gentle air movement around the pots does plenty to allow air flow in and amongst the LECA balls.

 

[big923cattleya]

I have been at this orchid growing game and I have to say that orchids are completely different from other plants. They are not going to be happy with automation.
Why automate anything? Well, obviously to make it easier for you, the grower. Well orchids don’t like easy!
It is just my opinion based on my 5 decades of experience. We orchid hobbyists are a weird lot!!! We take these beautiful plants, some from SE Asia, some from the Philippines, some from Africa, South America and Central America and we make them grow together. At least we try to!
I am not really comfortable with that notion.
And once you substitute sensors and automatic controls for good ole observation and experience, that’s when it all blows up in your face.

Observation, experience, acquired knowledge knows no boundaries!!! It is just an opinion from an old experienced grower, teacher, and lecturer. You want to retain as much control as you possibly can. You might want to think twice in terms of turning it over to machines.

 

[Ray]

@big923cattleya , I think you're being a bit narrow-minded in that opinion. Can you just slap any old orchid into an automated setup and have it thrive? Of course not, but it is possible to set up automated systems that can keep the plants happy - after all, if one's "observation, experience and acquired knowledge" is adequate, those systems can be appropriately designed.

I am in that 50+ years of orchid-growing demographic, too. Over time, my understanding of the needs of the various plants I had improved to the point that through selection of container (or not), potting medium and growing technique, I was able to greatly simplify my care by watering everything at the same time. The last 12 years before I retired, I had the "pleasure" of a 50-mile, one-way commute on the PA Turnpike, and watering at 5 am and getting soaked is no fun, so I set up an overhead "rain" system that I could activate remotely, have it irrigate everything for 30 minutes, then shut off. It worked quite well. Fertilizer was metered into that water automatically. Those plants grew and bloomed very well.

Having said that, I still had to be observant of the sunlight and temperature to help me decide when watering was appropriate, agreeing with your stance, just not painting with such a broad brush.

 

[big923cattleya]

Well if the system works for you then it works for you.
I need to inspect my plants on a regular basis. Bugs indoors can blow up overnight it seems. To my way of thinking, hands on inspection has no equal.
I grow a lot of Phalaenopsis, so many of them seem to grow well without much in way of care. But every now and then, the health of one seems to go down quickly. The roots are compromised, often in bad shape, and the leaves go wrinkly fairly quickly. I prefer to stay on top of things.

 

[Ray]

I'm right with you on hand inspection, but that gets more difficult with a larger collection. My automated "rain" system was employed in a greenhouse containing as many as 1000 plants of many genera, so having that one, time-consuming task automated gave me more time to do such inspecting.

Since downsizing and relocating, my collection is about 3 dozen plants, mostly phrags and paphs in semi-hydroponic culture using a LECA medium, plus phals in traditional culture using LECA with about 25%-33% rock wool mini cubes. With moth of those media choices, there is no risk of decomposition and subsequent root suffocation.

 

[big923cattleya]

Well, I have not used rock wool for 40+ years. Glad some body has luck with it.
I use the following:

I pot according to what I call the “Oreo method”! Some mix in the bottom of the pot, then a healthy layer of sphagnum, then I top dress with the mix. My Phragmipediums and Phalaenopsis seems to like it under lights.

 

[monocotman]

What’s the thinking behind this oreo method?
david

 

[big923cattleya]

Well it started in Florida really. Me, an orchid judge, killing Phalaenopsis like a World War 2 ace!! I couldn’t use bark since down there with a rainy season, it was rotting inside of 6 months!! So I went to a media that wouldn’t completely break down.
I chose Leica, charcoal and perlite mostly. The rains could come and my Phalaes seemed to thrive. My Catts loved it! So here in Michigan under lights, things dried out very, very quickly. Household humidity is 19% during the winter. Phalaes seemed to demand water every day! I haven’t got time for that so I played with this mixture trying to extend the time between waterings.
I came up with this Oreo business about two years ago. My Phragmipediums seem to be thriving. I am watering generally once every 5 days and feeding every third watering.
My Phalaenopsis get water twice a week or every 4 days. They are doing pretty good too!
Well, it seems to be working well for me. My Phragmipediums go outside for five months, May through September, and when they come back inside, they seem to be in very good health.

A good friend of mine out in California, north Bay Area, had trouble keeping his plants wet enough. He travels a lot each day, works late and has trouble maintaining a watering schedule. He is trying this method on his slippers and Phalaenopsis and he reports much better growth and flowering. He tried it starting 9-10 months ago.

 

[monocotman]

Very interesting, thanks!

 

[Ray]

Well, I have not used rock wool for 40+ years. Glad some body has luck with it.

That's funny, Bill. I started playing with rock wool about that same time period. (I am a ceramist and ceramic engineer by education and started my career with Corning Glass, so you can understand my interest). It came as loose batting, either hydrophilic or hydrophobic. I tried all sorts of combinations and only resulted in suffocating the roots of everything I tried it with.

I became a big fan of LECA (another ceramic product) when business kept me on the road 6-7 days a week for 3-1/2 years, as it allowed me to automate the watering when I wasn't there. It was only after moving here that I found sphagnum to be a better medium for my phals in this environment, but it decomposed too rapidly, so I started experimenting with rock wool mini-cubes as a substitute. I found that they compressed too much from overhead watering, so started playing with a blend of the 1 cm cubes with the similarly-sized LECA pellets, and that has worked really well.

 

[big923cattleya]

What is the old saying? Oh yes, there are many ways to skin a cat. But in this case, there are many ways to grow orchids. Anyway, that seems to be the case.

 

[Ray]

 

[spujr]

Hi!

Ray, thanks for your comments, I was curious to what you think of this setup given your expertise in this area. You raise a good point, but just curious, if one was fine with changing out the LECA for frequently to avoid the mineral buildup, do you think this would work? My thinking is with the increase of water evaporation and air movement the orchids would have faster growth. In non-orchid aeroponics improve growth is seen. Of course orchids are different but just a theory.

In any case, adjusting the fans to run sporadically should help avoid too much rapid evaporation while maintaining good air movement.

Big923 thank you for your input as well and sharing your mix. I fully agree with you yet the scientist in me wants to control the variables and standardize as much as possible. In like many things, there's a balance, on one end is the plant and forget, and on the other is the nit-picky-fuss-over everything. My idea is weighted towards one side of the spectrum in light of business travel where I cannot be around to water or fuss over them. However I do agree with you that one should regularly watch and monitor how the plants respond to culture care. I personally haven't had much luck with either rockwool or LECA but enjoy trying new things out in the never-ending quest for good orchid care.

 

[Ray]

My thinking is with the increase of water evaporation and air movement the orchids would have faster growth.

Keep in mind that water, not air (or fertilizer), is the driving force for growth.

If the water supply at the roots is sufficient, hormonal signals are passed to the stomata to open, allowing more air (and CO2) into the process, and carbon fixation is "growth". If not, they close down to slow water loss.