This is a very simple sub-irrigation planter using two plastic containers. These happen to be utility/storage boxes from IKEA. I’ve seen them there many times in a range of sizes. You will also likely find something similar in a dollar or thrift store or make them from recycled food containers. The possibilities are limitless.
The photos are from Instructable.com. It's interesting to me that the idea is from Switzerland. Most out-of-the-box horticulture ideas I find are from outside the U.S. where people are free of the largely antiquated advice of our horticultural establishment.
I have one note of caution about these boxes. They are not UV resistant plastic. This is not a problem indoors but it is for outdoor use. Sunlight will make the plastic very brittle and the boxes will crack. You might consider wrapping them in a covering of burlap. You can even buy it in colors at a fabric store. Buy some polyester batting material for wicking while you’re there.
I have a collection of clear plastic food containers. Two cookie containers will make the same type of sub-irrigation planter as these boxes. I would use polyester batting material instead of string. Simply cut a couple of slits in the bottom of the inner container and insert a 1” wide strip of material in one slit, across the bottom and out the other slit. I’ll make one, photograph it and add it to this post later.
The only limiting factor is your imagination, which hopefully has not been dulled by the incessant mantra of "make sure you have a drain hole”. It is utter nonsense. Prove it to yourself with a pop/soda bottle planter and you'll be free...free at last!
