Yes , the flowers can be harvested.
This is the harvest tool, click on it then click on the flower to harvest it. Your flowers will be sent to your Harvest & Products Storage where you can either go to market to sell them or if they are ones that have a use, you can keep them and use them to make something in a facility to make more coins.
A faster way to harvest flowers is to buy a flower harvester. These are explained in the following link...
https://r1.slashkey.com/forum/showth...42#post5153542