I plant in 3 gallon pots also. When I first water her, I just give a little on the main plant and then water around the edge of the pot. This will make the roots chase the water. I find doing this helps establish a good root system. Then I begin with a full watering to runoff once they are established plants and ready to go. I also get a feel for the weight of the plant when it is dry, this helps not to over water her.