After a short period at the Danish Academy (spring 1884), he attended the Kunstnernes Frie Studieskoler (1885–1891) where he was the first of the Fynboerne to study under Kristian Zahrtmann.
His travels included Sweden (1899) where he visited Johannes Larsen, Germany (1902), Italy (1905) together with Jens Birkholm, the Netherlands and Paris (1908) and Pisa (1910–1913).
Together with Johannes Larsen, Poul S. Christiansen and Peter Hansen, Syberg was one of the first Funen artists to study under Zahrtmann who had broken away from the traditions of the Danish Academy to venture into Naturalism and Realism.
Initially he was influenced by Zahrtmann's colourist approach which can be seen in Dødsfald (1892) depicting his mother's death in Fåborg's poorhouse 14 years earlier.
Thereafter, his oils include Dødens komme (1906) and Døden ved vuggen (1907) and landscapes depicting scenes from Funen, first around Dyreborg and Svanninge such as Forår (1893) and Aftenleg i Svanninge Bakker (1900) and later the area west of Kerteminde where his garden and children were the main subjects.