Yes! While pots can only be used on one plant at a time, they can be swapped between plants as much as you'd like. Pots can be used for your current plant, greenhouse plants, or plants placed in as decor in your rooms. You'll always have access to them and they can be used over and over. 

Pots can be swapped by clicking on the change pot button on the bottom right of the watering screen. To change a pot from the greenhouse, select the plant and top the 'change pot' button.