I looked the term up, and instead of each tomato going on the inside of a wire structure the tomatoes are planted on the outside. The other difference is that the inside of the wire structure is filled at least partially with compost. When the compost is watered the water flows through it and soaks in around the tomatoes, watering and fertilizing at the same time. Photo 1 shows a traditional JTR, and they are usually heavy wire with a 6x6 grid. You can use any type of wire fencing. Welded wire (2x6) is stiff enough, but adding some sturdy stakes as in Photo 2 will stiffen even poultry wire. Remember that whatever diameter you want for the center should be multiplied by 3.14. A desired 2ft diameter times 3.14 equals 6.28ft, which requires about a 6ft 4in length of fencing. A 3ft diameter requires a 9ft 6in length.