Frederick Blackman was born in Lambeth, London to a doctor. He studied medicine at St. Bartholomew's Hospital, graduating MA. In the subsequent years, he studied natural sciences at the University of Cambridge and was awarded DSc.
He conducted research on plant physiology, in particular photosynthesis, in Cambridge until his retirement in 1936. Gabrielle Matthaei was his assistant until 1905. He was elected in May 1906 a Fellow of the Royal Society, his candidature citation reading "Fellow of St John's College, Cambridge. Ex-Lecturer and now Reader in Botany in the University. He has made distinguished investigations in physiology of plants, of which the following may be mentioned: Experimental Researches on Vegetable Assimilation and Respiration, viz: - On a New Method for investigating the Carbonic Acid Exchanges of Plants (Phil Trans, 1895); On the Paths of Gaseous Exchange between Aerial Leaves and the Atmosphere (ibid, 1895); by his pupil, Miss Mattaei, On the Effect of Temperature on Carbon-Dioxide Assimilation (ibid); A Quantitative Study of Carbon-Dioxide Assimilation and Leaf-Temperature in Natural Illumination (Proc Roy Soc, 1905, with Miss Matthaei); Optima and Limiting Factors (Ann of Bot, 1905); On the Reaction of Leaves to Traumatic Stimulation (ibid, 1901); and other papers. In 1921 he was awarded their Royal Medal and in 1923 delivered their Croonian lecture.
He was buried at the Parish of the Ascension Burial Ground in Cambridge, with his wife Elsie (1882 - 1967).
Blackman proposed the law of limiting factors in 1905. According to this law, when a process depends on a number of factors, its rate is limited by the pace of the slowest factor. Blackman's law of limiting factors determines the rate of the photosynthesis.
Suppose a leaf is exposed to a certain light intensity which can utilize 5 mg. of CO2 per hour in photosynthesis. If only 1 mg. of CO2 enters the leaf in an hour, the rate of photosynthesis is limited due to CO2 factor. But as the concentration of the CO2 increases from 1 to 5 mg./hour the rate of photosynthesis is also increased along the line AB.In this case CO2 acts as a limiting factor.