Until 1850, Whareroa was used for horticulture by Māori, who established their pā sites on the flat land.
The area was first farmed by Alexander MacKay in 1850 and it was later passed to the Wellington Hospital Board as a potential site for a chest hospital. In 1942 Whareroa was acquired for defence purposes and became a training and recuperation camp for US Marines fighting in the Pacific campaign.
After World War Two the Lands and Survey Department developed Whareroa as a public recreation and education farm park. In 1987, Lands and Survey underwent restructuring and was divided to form Landcorp and DOC. Landcorp managed Whareroa and it was closed to the public.
The formation of the Whareroa Guardians group in 2003 resulted from a community campaign to prevent the Farm from being sold for private development by restoring it as public land. The Guardians' campaigning was successful and in 2005, the Government purchased Whareroa to be managed by DOC.
The Whareroa Farm Plan (PDF, 9,000K) ensures it is sustainably managed.