Why I think bark is the worst media for orchids

[ChrisMalaga]

I've been growing orchids for 10+ years, with ups and downs (moved to another country, lost many, had a time when I thought I would stop growin orchids, now I'm back, some are still with me after 10 years...) and, as many people, I've been using mainly bark for my orchids. I've used of different qualities (from decorative bark chips where I had to select the best chunks manually, to superior grade bark from orchid nurseries, but never Orchiata, so I can't really speak about a substrate that costs more than orchids). I usually use medium sized bark, fine bark is "better" at some things (retaining moisture, wicking, etc), but suffucating for large roots. I'm now considering that most of my bad experiences are related to this media. I will explain why and also my final conclusions about what is really wrong with bark, at least for me (everyone has a different environment and techniques and I'm sure many people will disagree 100%):

- new bark doesn't retain enough moisture. Things get better if you soak it before use and if your watering technique is soaking, especially for the first months. When bark starts degrading, it will retain more moisture... until it's too degraded and acidic and it's time to change it again. I hate soaking plants, especially considering water is so expensive in my area and ecologically wrong to throw water, and also time consuming.

- moisture is very uneven. Bark is not a really wicking material and a wet area remains wet, but you can have dry chunks beside and they will remain basically bone dry.

- it is hard to tell when to water your plants. Now this is a big NO for me. I've made tests, putting bark in empty pots, watering and leaving it there for a week. Then I checked the medium: while the top and side layers were visibly dry, due to evaporation (I always use pots with side holes), the core was still wet. You cannot see in the middle of the pot, so you need to guess. Droplets are visible on transparent pots? That really depends on temperature, you can't rely on droplets either. And still: some parts of the medium will probably be bone dry, even if you see droplets.

- it allows the creation of small water pools in the media, where bacteria can proliferate and water can suffucate roots. This happens especially with medium and large sized bark and is related to the biggest fault bark has, in my opinion. It also has to do that it's an organic media which is also a good environment for pathogens.

- now the biggest fault. The SHAPE. Bark has an irregular flat shape (there is less flat bark, but more or less, it's flat pieces). When you put bark in your pots, it can be aligned vertically, horizontally or somewhere in between ("obliquely"? English is not my first language, sorry). Unfortunately there is no control over how those pieces will be aligned, unless you want to put every single little piece of bark in your pot with extreme care, which is close to impossible. When a flat surface is positioned horizontally, water will sit on it for an undetermined amount of time, depending on your temperature and evaporation rates. This is especially true with new bark, which is less moisture retentive. I find this to be maybe the biggest reason why I've had problems with bark. A huge drop of water sitting for hours or days on a piece of organic media, has caused many pathogens to proliferate in my experience. How do I know if there are huge drops sitting in the middle of the pot where I cannot see? I can't know, but I'm sure there will always be.

One of the solutions I've tried was to add other material to bark: sphagnum, leca, pumice, perlite. While these can improve the situation to some limited extent, why should I add something to improve the material, if this material has so many faults and will also degrade faster? I prefer adding sphagnum to something else (leca, scoria, etc.) to tweak something that already works, than trying to find a solution to something that doesn't.

This is why I'm growing less and less orchids in bark and having more success with alternative media (leca, scoria, pumice and even sphagnum). I don't know if other people will share my experience, but I still find incredible that 99% of people use bark, with so many downsides. I know it's my personal experience though.