If you collect a specific kind of plant, or just like to remember what you planted, the best identification markers are the permanent aluminum stake/signs. We have found that 10" tall is the best size. They're easy to write on and they're not shiny so you don't see a glare of metal overshadowing your prize plant. My old rose collection has been labeled with them for 12 years. I haven't had to replace any stakes and the writing is still like new. I write on the aluminum stakes with a black wax pen. Ten stakes per order. Ten for ten...Use Black Wax Pencil