Drill a 1-3/8" hole in the bottom and run a 1/2" PVC pipe up to 3" from top and then add a drip adapter

It looks like they have a self watering system already. You could bury a hose, and run it up through the bottom of these troughs. I think that would be a really great idea for a garden. It really keeps everything organized so much better. http://www.desertgardensinc.com

Need to figure out how to get that water wicked up to the planting soil for the roots to find it. That's the tricky part. I'm planning on getting some already self-watering planter for the front porch and I'll suss out how they work that. Then I can steal the idea for the troughs.

I am wanting to use my existing sprinkler head and put in a drip system in these. Perhaps connect it to a drip system...Putting rocks, about 2-3 inches, then gardening cloth over the rocks, so it doesn't clog the drain hole. Attach a hose the the drain hole and put it on plants that are in the ground. Just hoping this works, it does in my mind!