I'm working on getting my java fern into order, as it's scattered (and mostly growing unattached to anything) all over my tank. I've noticed that many of the plants have very long sections of rhizome (at least 4-6 inches) with no leaves left. Can I trim off this old rhizome? I know that I can propagate the plant by cutting the rhizome between leaves so I wouldn't think it would be harmful, but I wanted to double-check. Thank you!