Some plants flower in response to cold RIation refers specifica by a period of low temperature. Winter annual (Winter cereal) Winter strains planted in the spring would normally fail to flower Biennials. Biennials are normall flower and die in the second season, again following an overwintering cold treatment In either case. the cold treatment appears to be effective only in the FR 5AM meristematic zones of the shoot pexSome plants flower in response to cold Vernalization refers specifically to the promotion of flowering by a period of low temperature. Winter annual (Winter cereal): Winter strains planted in the spring would normally fail to flower Biennials:Biennials are normally flower and die in the second season, again following an overwintering cold treatment. In either case, the cold treatment appears to be effective only in the meristematic zones of the shoot apex