The best way to check if a plant needs water is to feel the soil a couple of inches down. If the soil is moist, don't water. Overwatering starves the plant of oxygen and is usually fatal. A new plant in sun dries out faster than one in the shade. A windy site dries out faster than a protected one.
Sandy soil dries out faster than clay soil.
A layer of mulch helps retain soil moisture. Plants under roof overhangs may need ongoing watering. Plants will need water in years ahead if summer drought of over two weeks occurs. Plants need fertilizer every year for good growth and health. Always follow the labels on the type of fertilizer you use.