Why do you think she would have burned the scales? She was applying it to the Quack Grass, correct? Not the lilies, right? Roundup ties up when it hits the dirt, which means it won't move through the dirt to other plants. It's a contact herbicide as in you have to touch the plant you want to kill with it and that plant "ingests" it and it will slowly kill that plant and only that plant. Paint brush was a good idea.
Like Leftwood, there isn't a good time for me to spray a bed in the spring without killing something I don't want to kill. However, I do use a selective herbicide, like Grass B Gone or Over the Top, or something similar, that targets grass and only grass. It takes about three weeks before you see any effect, but it does work. I use it in my peony, lily, iris, and daylily beds. I also use it in my hosta beds. I've never had a problem with it. You just have to stay with it. That's where I fail, I tend to get distracted with something else....
