Once they have roots, I harden them off. First, you have to let them get used to breathing on their own again. So take the plastic off a little each day. Punch some holes in it if you can. Do this for a week or so, then set them in the window or under lights. Once the danger of frost has passed, you'll want to harden them off again to the outdoors like you would any plant that's spent the winter indoors.

Okay! Thank you!

A nice foliage growth on your cuttings is not a measure of root growth. Take off the plastic for an hour and see if they wilt. If they do, put the plastic back on for a week, then try again. When you can leave the plastic off without wilting you probably have roots. Within a few days I would pot into individual pots of potting soil and water well. Next week I would fertilize with a weak liquid mix. It is not critical but I like a 3-1-2 ratio of NPK. Al