Irrigation grids define your planting area while delivering water to each square foot. No water is wasted being applied directly to the base of the plants. This is extremely efficient and better for the plants, not to mention it saves you from having to manually water the garden! Put a timer on it and your worries are over. It’s impossible to over-water with Mel’s Mix as any excess water just drains away. Watch them in action 4×4 Deluxe In Action