Thanks to all of you who replied re this. It's been very helpful info
thanks.

We just need to make sure (I'm guessing here) that we need to not let it
get high enough so that it gets to a re-seeding point because the
neighbouring property owners apparently worked hard to (mostly) rid
their places of it. We don't want it to spread to theirs (which was
indicated subtly by one of them.)

Thank you all very much.

L.