How late did Flower-class construction begin?

Did the Royal Navy begin the Flower-class programme too late?

Yes. Design work began around 1937-38, but 1939 orders and construction were still roughly one or two years later than ideal.

British escort preparation crossed into a late response rather than an early precaution. The Flower class drew on interwar sloop development and began to take conceptual form around 1937-38. Orders were issued in January 1939, while construction began in July. That timetable still put useful ships into production before the war had fully unfolded. Starting the programme one or two years earlier would have provided a materially stronger escort position at the outbreak.