Hit it with a 2 X 4 to activate the stress / the urge " to propagate" and set seed/ flower in the plant for next year .
If you hit it with a roll of newspapers , it might just think you're fluffing a pillow so it will sleep well all winter .
You want to "shock it to me " ( Laugh In,TV , early 70's )with vigor ,without terminally damaging the plant , best done at 'leaf-out' , prior to flowering in springtime .
Question ? Was it on this forum that someone wanted to propagate lichens and moss ? I recall seeing a photo of a fence and wanting information... ?
Some folks I knew in Marble Falls, TX that grew greenhouse tomatoes for grocery stores would go through the greenhouses with a chainsaw fired up, threatening to kill the plants. They swore it worked to really up the tomato yields.