I dont recommend freezing the greens lose nutrients and veggies still become slimy. What I do is take the greens I am using (collard, mustard,turnip, ect..) I wash them and dry them good. I cut them up to appropriate size and fill up ziplock storage bag. I put a couple layers of paper towels on each side of ziplock bag between the bag and greens. I make enough greens that they usually last a 7-10 days before they start to go bad. If the paper towels start to get really soak just change out for new ones. Best way I found to keep them without them going bad. Also I like it because dont have to cut up greens everyday for all my dragons. That is what I do for the base greens of the salad anything else is cut up sepertly and stored in tupperware to be added as needed(squash,carrots,fruits, ect..).