For the simplest version of this hack, sand the edges of the broken shards with fine-grit sandpaper, then get a Sharpie pen and handwrite the name of your plant.
However, you can customize these markers to your taste to create a fun, personal stamp — for instance, by adding stenciled designs, fabrics, different background colors, and more.
Lastly, you should add multiple thin coats of Mod Podge to help seal your new plant markers. Let them cure for 72 hours before placing them next to their corresponding plant.