If you were not around during the event period of the previous plants or could not complete the sequence of the plant up to level 12, then be informed that we may not recycle the previous flowers. However, this is not decided yet, and thus, nothing is confirmed for now.

Most likely, they will be coming back but maybe 10 -12 months later.

🙋 What to do with the remaining plants on my board, then?

Selling them or keeping them is up to the player.
If the previous plants do come back with a new event, then, most likely, the event will run for 2 months, which gives plenty of time to make up to level 12.