Towards the end of the 19th century he settled on Java in the former Dutch East Indies. In 1900, at the age of 23, he started working for the Koninklijke Paketvaart Maatschappij (KPM). He married Wilhelmina Louise Visser (1871–1913) in 1903 and they had two sons, the first in 1905 and the second in 1906. In January 1906, Heyne was appointed chief curator of the Museum voor Economische Botanie (Museum of Economic Botany) in Buitenzorg by Melchior Treub, the then director of 's Lands Plantentuin in Buitenzorg. In January 1920 he married Ida van Oorschot (1875–1957). In 1926, Heyne resigned as curator and in April 1927 he repatriated to the Netherlands. He and his wife went to live in Bennekom, where he bought a large house.
He added two greenhouses, one heated and one kept temperate. There he cultivated Indonesian plants till his death twenty years later. Heating the greenhouse made him rise at four, every night, to refill the coal-burning stove.
