I realise this is probably an unusual question, perhaps even odd, but I'm quite serious. I live in western Pennsylvania, and I have a small lot of lightly wooded land that I want to make un-navigable for practical purposes, with as little effort on my part as possible. I am looking for ideas for fast-growing, fast-spreading, durable, dense and generally antithetical-to-foot-traffic plant/weeds, so it will look and be far more trouble than it's worth to traipse through by the local riffraff until I am ready to do something with it. Nothing that will grow in the environment is off the table: thorns, allergy-inducing, the nastier the better.
So landowners, what's your nightmare weed?
So landowners, what's your nightmare weed?