To tell wanted plants from weeds pull both kinds out. those
that come up again...are weeds

Shopping for plants in a new garden center we ask an employee whether the store offered any kind of guarantee if the plants didn't survive. Oh yes he's printed on the back of our
receipts. satisfied we completed our purchase and left.
it wasn't until we got home that we actually read the receipt. It
stated.....we guarantee our plants to grow...or die trying