* cuttings take better if you are at the stage where buds visibly swell, but have not broken open (committed themselves to leaf tissue). You are probably zone five so it ie a good time to do it. I am zone four but pruned so some are going
* roots like their feet warm/ not hot making humidity condense, if you have condensation as in the sun there is a risk of mold taking over
* I have done community pots and individual long sleeves. This year I cut some four inch pipe by ten long, put a newspaper bag in the pipe, filled the bag with potting mix, treated cuttings with rootone , and inserted to the bottom.
I have enough length to have two nodes on all cuttings and some have three nodes
* once leaves pop out I will take the bag off so that they do not mold
I have given the neighbor a pail of cuttings in water and they took off in the water,, grapes are fairly easy to root so using Rootone can be overkill, ,,, but then I have been working at this bottle for fifty years and ought to finish it.