It is only possible to have one plant growing at a time on top of the Tree of Life! If you wish to change the currently growing plant, you will have to delete the plant that has already begun growing. To do this, please follow the steps below:
1. Tap the plant icon in the top left corner of the Plant Nanny app's homescreen
2. Locate and tap Delete This Plant
Don't worry about your hydration history! Only the plant will be deleted, and your progress will be preserved.