Cornus mas in nature grows mostly on south-facing hills and likes a lot of light and sun. It grows a lot of time on rocky soils sometimes dry. On another hand, it is the first tree in the garden which shows when it is too hot and dry. New green, not hardened branches soften and bend down when it is too hot and dry. In my experience, you can water them a lot and it is not possible to overwater them in the inorganic substrate. In summer with temperatures above 30°C, I water them three times a day. If not watered sufficiently during the summer edges of the leaves could be damaged and dry.
