2nd picture of my mystery plant Can anyone ID this plant? It is only may 28th and it is already well over 6'.
The experts must all be asleep. Be very careful with this plant until they confirm its identity. It looks like giant hogweed to me, which can give you a terrible rash.
I agree that your monster is Giant Hogweed, AKA Giant Cow-parsnip, which as stated can cause a serious rash and blisters if you handle it and are then exposed to sunlight. For more info see http://www.agf.gov.bc.ca/cropprot/gianthogweed.htm. Although it is very striking, you should remove it, carefully, while well dressed, and preferably on a dull day. Our native Cow-parsnip is smaller; a mere 1 - 3M tall and has less divided leaves. It can also cause mild photo-toxicity in sensitive people. As a children in North Vancouver, we called it "Poison Indian Rhubarb". At the time I had no idea what (if anything) was poisonous about it. We did pick it and although we never ate it I don't recall anyone getting a rash.
As it says at the page linked to above it dies after flowering, making it monocarpic rather than perennial.
