Use a soil mix that is 1 part potting mix or peat moss to 1 part sand or vermiculite. Add soil to the pots you want to use and dampen thoroughly. Check to make sure there are no dry areas in the soil.
Cut at least 2 inches (5. 1 cm) below a leaf node.
Place your potted cuttings outdoors if your outside temperature ranges from 60 to 80 degrees F (15. 5 to 26. 7 degrees C) and you have an area available protected from wind with partial shade. Keep potted cuttings indoors if you are experiencing hotter or colder temperatures. Make sure the rooting hydrangea cuttings receive partial or filtered sunlight. Keep soil moist, but do not over water. Hydrangeas prefer not to dry out, but they also prefer not to be in any standing water. [3] X Research source