Maples, My understock is potted in 4" pots and stored outside in an unprotected location. About 3-4 weeks before grafting I bring them onto an unheated porch. This lets them begin to dry out a little, and the porch is warmer and protected from the wind. In fact, once I move them to the porch they will get no more water til after grafting. About 10 days to 2 weeks before grafting I bring them into the Studio, which is heated to 60-65 degrees F (15-18 degrees celsius). After a few days in the warmth I cut the tops off to about 18" and allow them to bleed. At this point the understock look like bare sticks - no side limbs. Still no watering! About 5 days before grafting I cut off a few more inches from the top of the stem and let them bleed again. By the time I'm ready to graft, the bleeding should have stopped and the potting soil in the pots should be somewhat dry. Do not graft if the plants are still bleeding - its a sure way to kill a graft. The pots should feel relatively light when you pick them up, but the soil doesn't have to be bone dry. In fact, its better if its not bone dry. At this point you can lift a few understock out of their pots to see if any new, white roots are showing. If there are, this is a good sign and they are ready for grafting. If not, you can wait a while longer or go ahead and graft - your preference. I've had success with understock that had no white roots showing. If they've been warming up for 3 weeks or so they should be ready. After grafting I do not give the plants any water for a week. After a week I do give them a few sips of water - 3-4 tablespoons to a 4" pot. I water them like this twice a week for the next 4 weeks. I also mist them a couple of times a day. The idea is to keep just a tiny amount of moisture in the soil until the grafts have healed. Once the grafts start sprouting I slowly begin giving them more water. Not much at first - gradually increase. As the leaves unfurl and the plant gets larger increase the watering, but always stay on the conservative side. 8 to 12 weeks after sprouting, the plants should really be leafing out well and can be put on a normal watering schedule. If frost danger is past, I put mine outside in dappled shade where the automatic sprinklers can water them with the rest of my plants. Hope this helps!