Frank Jarman was appointed forest ranger at the Devil's Peak plantation, near Cape Town, in September 1894. He planted numerous trees on the mountain, mainly exotic pines and eucalypts, which are now being removed to restore the natural fynbos vegetation. From 1897 he made regular observations at a second order meteorological station for the Cape of Good Hope Meteorological Commission. He was also in charge of three rain gauges at different points in the plantation, and from 1900 an evaporation station. His observations were summarised in the Commission's annual reports to 1902. In May that year he became superintendent of the railway sleeper plantation at Elgin, but died in an accident two years later. An inquest into his death was held at Caledon.
In November 1904 a commemorative plaque was built into the remains of Jarman's house on Devils Peak. The inscription reads:
“In memory of Forester Frank Jarman, who, from 1893 to 1902, had charge of the forest work which covered this wind-swept mountain with trees. He left here for similar work in Elgin on the mountains opposite, and died as the result of an accident.
On the wall of this house which he built, and in which he lived, this tablet is placed by his brother officials of the forest department and by friends, as a record of his sterling qualities, and of his remarkable success as a forester. He found these barren stony slopes tree-less: he left them covered with forest.” (Reggie, 2010)