Rockwool cubes

Remove the plastic wrapping or not? Will the rockwool grow mldew underneath the plastic if left on??

I ALWAYS leave the plastic on . This prevents algae from growing and burning the roots . Mildew will not grow.

Hi Mr John,
I don't know if you're talking the tiny ones or the big ones. But my experience is with the 1" and 1 1/2" ones which I used for cloning and seed starts. I left the plastic on while the clones were rooting under dome (to help keep them from over drying)...but once planted in hydroton (E&F) I removed the plastic so that they didn't stay too wet...which can be a problem.
JD