Something like that has never happened before. The system has lost all the plants that were added prior to 6:15am UTC (1:15am EDT) and they can not be recovered.
Unbeknownst to me, I had a script that runs every night. It checks to see if any plants exist in the lists for which there is no corresponding plants database entry. If so, that means that the original plant in the database must have been deleted, so it then deletes the entry in the list. Obviously this script is obsoleted by this new feature, and shouldn't have been running, but I was not aware of it.
Consequently, at 1:15am the script ran and deleted all the plant entries that don't have a database entry.
To further make things unfortunate, my database backups occur every night at 3:00am. That means that the plants did NOT get backed up before this script ran. There is no way to recover the plants that were added over the past 24 hours.
To say I'm sorry would be an understatement. To the best of my recollection, this kind of data loss has never happened under my watch (in over 20 years of web programming) and is a huge embarrassment to me, and a major inconvenience for you, Seedfork, and the others who had plants lost. I can only apologize and assure you that the problem that caused this has been corrected and future plants added (or re-added) to your list are as safe as any other data on Garden.org.