He is best known for his Indications of Spring, the phenology notes in which he recorded 27 signs of spring, starting in 1736 and continuing for over 60 years. Successive generations of his family added to his work until well into the 20th century and this information now provides immensely valuable data to the UK phenology database, giving us a wealth of knowledge about how spring is influenced by prevailing weather conditions, This is now of huge interest in the climate change debate. Marsham was the first to record the effects of nature and seasonal change.
