Do you deadhead chrysanthemum?

[Rosemaryandlavender1]

Hello all. My lovely DH got me this huge pot of chrysanthemum (garden mums) approx two weeks ago. Since then with all the rain they have bloomed! Do I dead head them? They are currently in a pot in the garden. Any tips on how to get them to bloom over a longer period?
Thanks in advance

Keep on deadheading them. Water and feed and you should have weeks left in them

Thank you
Do I pinch off all the fully bloomed flowers?

Yes. Take them down to a leaf