Without seeing your holder and being a gardener, I would say it is probably not joined under the pot but one continuous strip. A seam under the pot would be where the weight is and that wouldn't be good. I think it would have 2 long strips that went from the ring and back to the ring, then sewn together on the bottom. Again I haven't seen the pattern. I'm just imagining how I would make one. I would use a very sturdy fabric too

I used to make Macreme ones. They had three ropes coming from the rings and a large wrapped knot on the bottom to support the weight.