Talk:List of drought tolerant plants

Hello, I seem to have found a bug in the logic being used. Achillea millefolium should be listed as a drought tolerant plant. But because it can be grown in multiple zones, it seems that it is being kicked out, and that may be happening with others as well. In looking at some of the other lists, I noticed that the List of Ferns look as "Min Zone", but not "Max Zone". Might that apply here as well?