Clear a site for the witch hazel that receives part sun and has well draining, moist soil. There should be enough space for the plant to grow without trimming, expecting it to reach the 15-foot width and height, even if it isn’t that big now.
Dig a hole in this location in depth to the size of the plant’s root ball, but twice as wide to leave room for growth. Set the removed dirt into a wheelbarrow as you dig.
Fill the hole halfway with water and watch for draining. If the water does not seep away or is taking a long time to drain, then select a new location and dig a new hole.
Compare the soil in the wheelbarrow to the soil clumped around the roots of the witch hazel. If the two seem different, then work the roots to loosen some of the old witch hazel soil with the soil of the hole. Mix the two soils together.
Set the witch hazel into the prepared hole. Add or remove soil to adjust the plant so it rests just slightly higher in the ground than how it was previously growing. Fill in any open space in the hole around the base of the plant with the soil from the wheelbarrow.
Water the area thoroughly to soak the soil and settle it as air bubbles are released. Add more soil around the plant if obvious dips in the ground appear from the soil settling. Water enough in conjunction with weekly rainfall to ensure the witch hazel gets 1 inch of water weekly.
Trim in the plant in early spring with hand pruners to remove dead branches or cut back branches that are excessively longer than others near it which distort the shape of the witch hazel. Cut back to just after the nearest fork and remove the excess or dead portion only.