Piloted last year, the "darkly comic" series follows an eccentric family of the same name.
The series will star Olivia Colman as wife and mother, music teacher Deborah; Julian Barratt as husband and father Maurice, the author of a series of twisted childrens' books called The Grubbs; and Sophia Di Martino and Daniel Rigby play 25-year-old twins Amy and Donald.
Channel 4 explains: "Flowers is an imaginative, cinematic comedy about an eccentric family, The Flowers, struggling to hold themselves together. Husband and wife Maurice and Deborah are barely together but yet to divorce.
"As Maurice fights inner demons and dark secrets, Deborah tries to keep the family together at all costs and becomes increasingly suspicious that Maurice is in a secret homosexual relationship with his Japanese illustrator Shun."
Channel 4 adds: "Maurice and Deborah live in a creaky, messy, crumbling old house with Maurice's mother, Hattie, and their maladjusted twenty five year old twins Amy and Donald: both competing for the same girl and continually failing to burst through the confines of their absurdly arrested development.
"Swinging from the magical to the mundane to the downright mad, the eccentric Flowers and their often self-inflicted crises are surrounded by even stranger neighbours who become the agents of yet more everyday chaos and disaster."
Writer Will Sharpe says: "I feel very lucky to be making this show with Kudos and Channel 4. They have been unfailingly supportive and have pushed me to make bold decisions on a show that seeks both to celebrate and to challenge the traditional sitcom format. This is a comedy about people who are struggling and the situations that can arise when you refuse to admit that there are problems. Our aim is not to make light of the darkness, but to find the light within it."
Channel 4's Deputy Head of Comedy, Nerys Evans said today: "Flowers is the kind of deliciously dark comedy we love at Channel 4. The word dysfunctional doesn't even come close to describing quite how brilliantly peculiar the Flowers family are. Will Sharpe's genius coupled with an amazing cast has led us to an unbelievably original piece and we are delighted to have it on the channel."
Naomi de Pear, who developed the series and will produce for production company Kudos, said: "Flowers has an other-worldly quality to it, even though it's about real characters and real emotions. I couldn't be happier that Will brought this dark, hilarious and emotional vision through our doors and it's been such a joy to develop and see it come to life with our extraordinary cast."