This plant presently grows in the Barrie area against an east facing wall beneath a dry vent and near an air conditioner.
– sandy loam soil
– stem goes about a foot to a foot and a half to a potato like bulb/corm that is about the size of a half fist.
– I have tried digging up every root in the past, but continues to come back.
– Although touched with my bare hands, doesn’t seem to leave any residue or mark.
– Seems to be very drought resistant.
– It has not flowered perhaps of my constant interference.
It is difficult to identify your plant properly without a picture of the flower and not being certain of the leaf. I don’t believe you have giant hogweed growing in your garden. If the leaves you have shown in the photo belong to the plant, they are the wrong size and shape. Please check out this website for pictures of the leaves. http://www.gnb.ca/0168/GiantHogweed.pdf
This plant is likely the Voodoo lily (Amorphophallus or Sauromatum) which is generally an annual in this climate zone, but it can survive cold temperatures and become quite invasive. The flower comes out first and is quite smelly. The flower will also capture and eat any insects that come to it. After the flower dies back, the leaves come on. As quoted from a forum on this species: “The main way that this species spreads is via asexual reproduction. The small tubers that are produced around the top of the main tuber create an ever-larger clump of plants. Vigorous weeding, cutting of foliage, even Roundup applications spring, summer, fall have only succeeded in making the little buggers smaller, albeit more numerous …” http://www.aroid.org/aroidl-archive/showthread.php?id=2875 Persistence in removing the corms as you see them and perhaps hoping for a very cold winter seem the only way to control it.
The following website contains additional information on this unusual plant : http://www.kew.org/plants-fungi/Sauromatum-venosum.htm