Seeing as I'm a phal abuser, I've also tried the plastic bag root recovery method, but it's never worked for me, I always end up with mold on the roots, and as soon as I see that I give up and toss them (usually within 2-3 days.) Is there a trick to making the plastic bag with higher humidity work?
Hi Kara, I suspect you leave the cotton (or sphagnum moss or whatever you use as media) too wet. I use sphagnum moss: some minutes in ambient temp water and then squeeze.
Fungi will not grow on healthy tissue. If you're seeing mold on the roots, they're on their way out so should be removed.
The idea behind "sphag-n-bag" is to slow the desiccation of the rootless plant while it begins to grow new roots. The sphagnum (or paper towel, cotton, etc.) is there simply to hold water for maximizing the humidity in the bag, and should not come in contact with the plant at all, so how wet it is is irrelevant.
Sit the recovering plant in the plastic bag but leave the top open for air circulation. Lack of air will cause mold problems.
Also keep the bag in a warm place but out of any sun light. If you put the bag in sunlight you have created a g/h effect and that too will cause an issue with mold.
I have a different perspective than Ray regarding mold. Mold will grow in any static area.