It can be almost as aggressive in a dish as it is in the garden. A light touch is essential when using it. And of course always plant with pot still attached - it won't stop the spread, but it can give you a fighting chance. :ermm:
It sounds like she got the point - this time, at least. And as everyone has already mentioned, the folks who were there for the +4 incident no doubt know who you meant. I thought your email was way more gracious than I'd have managed. It sounds like it will be a lovely time. :smile: