You can look at the original post to see which plants are currently supported. This does currently only state All herbs and All Allotments
Flowers and trees may follow after the OSRS Farming update has been pushed.
As for your can withdrawing; re-filling of watering cans has actually been implemented into this script. Please tell me more in a PM about what OSBot version, whether you're using mirror mode or not and I'd like you to give me a gif