Mine is categorized similar to Deb's, i too started out with just a large catch-all list like you
@HamiltonSquare, until it just became to unwieldy, I then figured which categories I would use the most. I even added a Trade and Want list, which is handy when I am at a nursery, I can check my list to see if they carry anything from my want list. In my notes section I often add where and when purchased. In my Want list I sometimes add a source or two in the notes section.
Funny how you get in a certain habit of doing things, I never use the category listing in the blue left side, I always use the center section and utilize the drop down menu a lot to access individual genus entries.
