Hello, well, this is my first time posting in this forum. I am new to growing chrysanthemums, and I got these ones from someone who reproduces them using the "mother plant" method, in which you cut the sprouts, let them root and transplant them to their final destination. So after a couple of months, there were buds in my mums and they started to flower, which was great! But somehow, the flower quality is not the desirable one, as you can see in the attached picture. I have them inside a greenhouse with average temperatures of 68 to 75 F, enough water and nutrients. Someone mentioned a possible boron deficiency, so yesterday I applied boron to my mums. Also in between the flowers I found thrips, so I applied an insecticide to control that problem.
Any help would be vastly appreciated.

Thank you