I have a small garden that backs up to a canal maintained by our city. A block wall separates the city land/canal and our garden. I've planted 47 flats of various ground covers and ALL have died. Likewise, with various plants planted along the wall. My soil has been amended and should be fertile. Could soil sterilizers used by the city be leaching through and killing my plants? Why are they all dying? I'm desperate for advice.
If you haven't had your soil tested, that's the first thing I'd to. Contact your local agricultural extension office to ask about having your soil tested.