Question
I live near Davenport, Iowa.  My next door neighbor planted zoysia grass about twenty five years ago.  It has taken over his property and now is taking over mine. We have a plastic barrier between our properties.  I am looking for an effective means of stopping the spread of this grass onto my property. Obviously, I do not share the joy of a brown yard nine months per year.

Thanks.

Answer
Cut a trench about 1 foot deep and 1 foot wide. It should have the shape of a check mark: a straight side down towards your properly (vertical) and then a 45 deg angled side from the bottom of your vertical side to the top of his side. E.g. like this: V (think of this V has having a vertical - not slanted - side on your side of the property).

You can put some light mulch in this trench, such as straw but do not use compost etc.

When the grass tries to send runners across the trench, you can use your edger tool (manual or electrical/gas) as cut through the runners. Do this every time you would mow your lawn. Also once per year "recut" the trench so it is nice and clean/clear.