Keep soil evenly moist throughout plant cycle when watering. If there is runoff you have watered a little too much or the soil has actually become hydrophobic due to not watering enough.  Once plant looks established, aim for even moisture throughout soil by using enough water per pot and adjust watering frequency to suit water consumption and environmental conditions. Don’t over water to the point of runoff. Mulch will help lower water usage and encourage beneficial microbes to cycle nutrients contained in your soil.