The first thing I thought of when I saw this was "an old swing set frame"... think GREEN & recycle! If you don't have one, I bet a neighbor/family member does & would be more than happy to see it go bye-bye! Plus, it can stay outside in the weather! They can be anchored against the wind, too. (something to consider as the tomatoes get bigger)... I, too, grow heirlooms & they do get TALL. I will be trying something like this; I like the general design. Happy gardening everybody!