Cost of shipping a dimensional object wide makes this something to make on site. A roll bender, 2 steel pipe and 6 pvc pipe are the main materials. The larger the diameter the higher the yield in the area.
Self watering hanging basket. The link shows putting a small pot in center and filling with water but I like the water bottle idea shown in illustration.remember to line bottom with plastic bag (between the soil and fiber or moss) - Gardening For Life