How long is unused potting mix viable?

[Tom Reddick]

Greetings all,

Hope everyone is well. With double duty on a couple of projects, I had to scale back a bit on the orchids this past year and have not been online much at all, but still going at it and now with more free time I have a small number of new flasks coming this week.

What I am wondering is if the batch of potting I have on hand- which is about 14 months old- is still safe to use. It is a mix of fir bark, charcoal, perlite and Metro-mix. It has been sealed in a container that lets in a bit of air- but there is still a bit of condensation under the lid and it is still slightly moist. Smells fine- no mold or mildew odors etc.

There is just enough to pot out these flasks for their first compot stage lasting about 6 months, and I am hoping to make use of it rather than toss it out. Grateful for any thoughts.

 

[Ozpaph]

I mix up large quantities of 'mix'. What's left over I use the next year provided its not moldy or overly wet.
If you are concerned - soak some in distilled water and measure the pH and ppm (but compare to new mix or existing plants)

 

[Tom Reddick]

Excellent- thank you. The mix seems good as it is, but I will do the testing you advise to be sure.