Hey DGC! If you want to re-use your plastic plant labels, don’t use a sharpee. Scrub
the plastic label with a pencil eraser until the finish is no longer shiney and becomes dull. This allows the graphite from a pencil to stick to the plastic surface. Use a softer grade of pencil, such as 5B, to make your writing darker.
Simply erase the label to reuse. I have used this method for many years outdoors in my pepper gardens.😉