Passive Irrigated Berry Bushes with Swales. Today, we're going to be discussing one of the most effective techniques for improving the health and yield of your landscape and your berry bushes: swales. Swales are essentially ditches that are dug into the ground to capture and retain rainwater, allowing it to slowly seep into the soil and nourish your plants. In this video, we'll be discussing the benefits of swales, how to design them for your specific garden, and the step-by-step process of digg