At the top in the bar with the Home page icon there is a drop down section called Tools&Apps. Click on Plant Lists. It will give you all the lists and also a "View and Manage your list" button. I am pretty certain you could create a list from there.
Under managing your list you can also set up categories for different plants (such as TB, SDB, Peonies, etc.). Then when you add a plant to your list it will have boxes so you can mark which type of plant it is. Example: Frosty Moonscape. Choose Add to my list. That opens up the Have, Want, Used To Have screen. After I hit "Have" I also check the TB box. This is useful if you want to search only part of your plant list.
