This is one of our two artichoke plants. We planted this one (along with three or four others that have since died) many years ago. The second is a volunteer that came up out in the vegetable garden plot a couple of years ago. It looks about the same as this one. I think we should pick one or two of the flower heads and see if they're edible.
Yesterday was productive. I mixed up ten liters (about 2.5 US gallons) of weed killer (household vinegar, salt, and soap) and sprayed all of gravel paths around the house and the driveway. Ken said he saw signs of death (yikes!) yesterday afternoon. The last time I sprayed this solution, it took a few days to a week for the weeds to die entirely. But die they did.