I have a spreadsheet of my irises as well. It is done by acquisition date of the cultivar. I have hybridizer, year, type (TB , SDB, ect) how many rhizomes, bloom time (E, M, L), from where w/date, and then special notes (like RE, PBF, DM award). Things like parentage and flower type (self, plicata) I can look up in various places and is not needed.
