I think I'd keep them in water so you can see if the nubs are growing, Deebie. Once they start to elongate a bit, you can pot them up and be sure the cuttings are still alive.
Are you keeping them warm? i.e. indoors on a windowsill? I've kept cuttings in water for literally months, and as long as they are warm, and once they have leaves they will even bloom in water. One time I stuck a cutting in a wine bottle (with water) and by the time I got back to plant it months later I had to break the bottle to get the mass of roots out.
