But it is useful.
There is a community garden project in Milwaukee that is pretty darn cool; Every spring, people can sign up for a little garden plot.
Those plots need to be numbered. Not something too permanent, but it has to be durable. It needs to handle the weather outside for the spring and summer.
I make laminated cards for this. But it's not quite as easy as it sounds- if you just laminate a page and cut out the numbers, water can get right in through the sides of the laminated card. The trick is to have a laminate border around the card.
Then we use a good thick outdoor double sided tape.
If you live in downtown MKE, you might have seen these garden plots around local parks.