We have a Black Walnut tree in our yard - and since the roots are toxic to tomato plants we plant them in large plastic pots. A couple of years ago we bought what I would call LARGE INVERTED CAGES. They have 4 rings with the lowest being 18inch diameter 2nd lowest 16 inch etc ... but still having the spikes on the bottom to anchor into the ground outside of the pot. We cannot remember where we got them, but cannot find them anywhere. Any help in finding / or identifying these cages if they are not truly tomato cages?? We are in the Chicago area. Thanks! John jcmas@usa.net