Is moist cork bark supposed to be squishy? - Orchid Board

lakester · #1 09-30-2020, 09:38 PM

Hi all! I just set up my very first vivarium specifically dedicated to my delicate orchids (mostly Sophronitis, Angrecoids, and Dendrophlax). Its a 18x18x36 tall Exo Terra.

It's currently going through its cycling phase before I put in my orchids but it already has misters, humidity control, lights, and internal and external fans setup. I'm slowly putting in more and more non-orchid plants and moss in it throughout this cycling process. It's having its first bloom of mold in it (though i hope it equalizes soon).

One thing I've noticed, now that the cork bark is always wet, is that the cork bark has become somewhat squishy. The main bodies of cork are squishy, somewhat like a fresh orange to the touch, and the parts of cork that are sticking out (like large bumps and fingers) and quite flexible although still require a lot of effort to rip off. Is it normal for cork bark to be like this when exposed to a lot of moisture? I'm hoping that despite this, the cork bark will still be strong for years and years to come.

Photo is the viv right before I put in non-orchid plants, ABG mix, and moss: Imgur: The magic of the Internet

rbarata · #2 10-01-2020, 05:26 AM

Although cork and bark are the same organ in a tree (with the same protective function), to us is not the same thing as the origin trees are not the same and its properties as a medium component are different. I suppose you are asking about bark and not cork because cork doesn't degrade easily and certainly not that fast.

lakester · #3 10-01-2020, 08:47 AM

Yup! Cork bark from the cork tree. The ones I have are called virgin cork bark rounds and virgin cork bark flats. Sorry if I was unclear. Is it normal for these to get slightly soft (as soft as a fresh orange to touch) when it's wet?

rbarata · #4 10-01-2020, 09:30 AM

I haven't noticed your photo before. Looking at it it's obvious you are talking of cork.
Cork is slight soft up to a certain point. If it's a small piece one can compress it but larger plaques like those in the photo you are able to compress it just a little. Then it gets harder.
Cork doesn't absorb any water so I think you are worried without a reason.

Ray · #5 10-01-2020, 09:46 AM

Yes, it’s perfectly natural for virgin cork bark to get soft when wet.

I have never used it in a way that it stayed wet, but it does “firm up” when dry.

lakester · #6 10-01-2020, 09:51 AM

Yeah, that's what I'm seeing too - right after I water it, it's somewhat pliant. But it definitely firms up once it's dried. My concern comes from the fact that the cork is going to be wet most of the time because of how high the humidity is in my viv (85%). It should be fine with a daily wet-slightly damp cycle yeah?

Orchid Kid · #7 10-01-2020, 10:51 AM

Just to boost your confidence in cork a little.... We use cork in petrol taps on vintage motorcycles, even the clutch plates use cork inserts... such amazing stuff is cork.

The taps with corks are soaked in boiling water to absorb as much water as possible and then lubricated with a little grease and then pushed into a barrel to form a seal for the petrol taps flow, and they last ages and ages if kept clean and wet (in this case petrol wet, but the water in the corks cannot mix with petrol) if you get my drift, lol.

In my mothers garden, there is a large piece of display cork that my late Father bought for the intention of mounting a Cattleya, but never got round to it. It has been out in the garden for at least five years, sun, rain, snow everything... and it is still good as new.
So! I reckon your cork will be fine!