I can't think of any good way to tie a marker to an Iris that would last any more than a season. Most of us use metal markers like these:
https://everlastlabel.com/inde...
I like this company... they are one of the fastest shipping places I've ever dealt with. Other folks like to do business with Kinsman or Lee Valley, and they're fine too.
You can either write on them with a soft pencil, or use a Brother tape labeler with UV resistant tape. The tape is easier to read. I'll often write other info on the back of the label w/ pencil.. The Ht, Season, Year and where I got it. I've got all that info on my database, but sometimes it's just easier when you're out in the garden to have that information in front of you. A word of caution: UV resistant marking pens & sharpies *may* last for a season or two, but fade while you're not looking.
There are other, fancier, bulkier labels out there... but these seem to hold up for as long as I need them to work.. (My older ones are 12-15 years old, and I can still read the pencil)
