I think you can still make it public or private but now I can't figure out how it worked. If you go to your profile and click on where it says There are 647 Plants in FrillyLily's plant list, somewhere on the left side of the page it should say View and Manage Your List; click there and then there should be an area that says Manage your Categories and at the bottom of that page there should be an option to make public or private. My eyes are giving me trouble today so I'm having trouble finding it again on my own profile but I know I found it earlier.