Using Capillary Action to feed my orchid barks water
 

I was thinking of putting several cotton wicks inside my pot spread around the bark and having it come out of the water hole at the bottom of my pot.

Then, I will lay the cotton wicks in a pool of water in the catch tray beneath.

The idea is to have capillary action feed the bark water whenever needed and all I have to do is feed the catch tray at the bottom.

Here is an article explaining the idea I am talking about.

gravity - What is the effect of water 'climbing' over a cup via a wet string? - Physics Stack Exchange

I would doubt you would have enough capillary action to keep the bark moist. All the air gaps between the pieces of bark would stop the moisture spreading.

Given it is not a common practice for growing orchids - I would say that it is not a successful method. But, try it if you want perhaps you may have come up with a new solution.

If you do decide to try it, use synthetic wicks, otherwise the cotton will rot and cause problems.

Having acquired a few African violets a year or so ago, I learned that the wicking method is popular as a means of watering those plants. (I don't personally use it but some do.) However, AVs are grown in a soil or soil-like mixture, much different than the media used for growing orchids. I think there is probably a very good reason why the wicking method of watering is not something you hear about from orchid growers.

Back when I sold Aquamat, I tried an experiment in which I lined a pot with the stuff, bunching it together and ran it out through an enlarged hole in the pot, and had that sitting in a tray of water.

Aquamat wicked very well, but the potting medium didn't, so only the perimeter stayed moist.

I later replaced that with a spiral of aquamat, spaced with EcoWeb, and that actually worked quite well.

Something about this bothers me. If you use these wicks then you'll eliminate the wet/dry cycle, keeping the roots always wet. You're inviting root rot.

Sorry, John. That's a myth. If it was factual, many of the equatorial species we know and love would all be extinct, as they can stay dripping wet for months at a time.

Water does not cause rot; suffocation caused root death, and then the dead tissue rots.

I have had plants in semi-hydroponics for decades, and they've never had an opportunity to dry out.

There is a difference between orchids on a tree and a pot full of bark. I could water my mounted plants 5 times a day and they would be fine. Water that pot 5 times a day and that will hasten decomposition and suffocating mush.

I would not do the wicking, at least not with bark. Maybe LECA?

Ray, doesn't that presume air exposure? Air movement would be drastically reduced under these conditions.

Eager to learn, I am curious as to why you would want to water them this way. I'm familiar with this method with African violets, as Mountaineer mentioned, but are you thinking it would save time? Or...? I am still very much learning here, but it feels like it wouldn't be a very good method of watering.... Just my:twocents:

OW & JK - Certainly if the bark is too fine or decomposed, the suffocation will readily occur, but if you use a coarse, durable bark like Orchiata, and change it often enough, it's no problem at all.

When I was growing in my PA greenhouse, I had things in Orchiata, LECA, baskets of loose sphagnum - you name it - and in the summer, they were watered daily, and had no issues at all.

Yes, I had to replace organic components more often than if they dried out periodically, but one significant advantage of NOT letting it dry out is that mineral buildup is minimized, if not eliminated altogether.

I grow herbs under a light using a 'wicking garden that I created with a clear reservoir, cotton clothesline, soldering gun, and container. The container doesn't sit in the reservoir but just above it and the rope wicks the water up into the soil, keeping it perfectly watered. When the reservoir is empty, I fill it. Before using this method, I always found it difficult to keep potted herbs watered. I think I will need to experiment with some lava rock and 'wicking' (without any orchids in the rock until I know if it works....)

It was an idea I came up with that sounded reasonable. But after reading the replies, I'll just stick with the methods that's has already been tested and proven to work.

Well, that's an opinion.

For reasons I've already stated, I still am of the opinion it is not a good idea with bark. Especially since I've no idea what kind of bark the OP uses, or other growing conditions. It seems like a Rube Goldberg way of dealing with the really simple process of watering.

One of the main principles of capillary action is that the space between particles is very small. Allowing surface tension and the adhesive forces to lift the water upwards. This will not work in mediums that have large gaps between particles, like bark and lava rock. It may work with sphagnum moss, if it is packed. This would work better with potting soil type mixes than chuncky bark type mixes.
I had a greenhouse professor in college that experimented with this type of set up to water annuals that they where growing for sale. Some times it worked and sometimes it didn’t. Plus the added cost for the extra components raised the cost of each plant. Which made this type of system inefficient and not very cost effective.

You and your professor are correct that, as a mass unit, most coarse media are poor at wicking, but that ignores the properties of the individual particles.

In the case of LECA, each particle can wick extremely well, and will transfer its moisture to particles in contact with it, resulting in a pretty good "mass wicking" scenario. Sphagnum is also excellent at wicking. Bark less so, but it is not entirely devoid of wicking capabilities, so if we go back to the OP's original premise, providing wicks that DO wick well to transfer moisture up to stuff that doesn't isn't all that crazy.

As orchid growers, where we get into trouble is when the spaces between the particles become small enough to hold moisture by surface tension. In that case, water fills the entire volume and suffocates roots. (Allowing the medium to dry out opens up those gas exchange pathways again, and that's where the myth that orchids must dry out between watering originated.)

if drying out between watering works why is it considered a myth

The myth is that orchids "require" drying out.

Sure, it is one way to compensate for a poor potting medium, or less than ideal conditions, but it is not a necessity, and certainly is not something that happens regularly to most of the equatorial orchids we grow.