The workplace culture (for example, missed deadlines, backstabbing coworkers, procrastination, blaming) is usually not something that we created consciously.
What transpired into a poor culture is a culmination of what the company has tolerated over time. Culture gradually teaches your employees what is tolerable and what is not. Employees learn the rules of the games.
Communicate the rules of the game often. Have the courage to have the hard conversation. Dismiss toxic people and you will end up with selections of people that promote positive culture.