I'm not really sure how fast it goes bad, but I have seen recommendations to replace your bottle of rooting hormone every year.

....and, in my hands anyway, I have never used, nor have needed, rooting hormones for hardwood cuttings and air layers. I use it most often with soft- and semi-hardwood cuttings, and ground layering (sometimes).

Good luck.

Decades ago we were taught in college laboratories that as long as the powder was kept dry it had an indefinite shelf life. We were taught to toss solutions after use. I don't recall anyone ever teaching why do it this way.

Now people sell solutions and recommend tossing the powder. I don't recall anyone ever boasting that they knew why. My gut says its marketing. You will buy more if they sell solutions and recommend tossing the powder.

maybe its the steril part?? i was watching a video on youtube and a guy shows that he has people use a spoon to dip the horomone into. and to use a smaller spoon.

The powdered hormone keeps as long as it is dry and has not been contaminated. The small amount of the powder to be used should be taken from the bottle and what is not used should be discarded to prevent contaminating the entire bottle. The liquid hormone that requires mixing a small amount with water should be used within one day and thrown away if not used. Al