Forest gardens (FGs) are tree-dominant land uses in Sri Lankan farming enterprises. Although FG financial performance has been described, their overall contributions to farming enterprises remain unclear. This information is critical given the global quest for financially viable, sustainable agricultural models. Farming enterprises include On-farm (land uses: FGs, paddy, cash crops, plantations, swidden/chena plots, livestock), Off-farm (employment, trading, grants, welfare) and household components. Forest garden financial performance was compared with other enterprise components in short-(reference year, 2012–2013) and long-terms (beyond 2013). Financial data were collected for 85 farming enterprises in nine locations of the Intermediate zone using Household Income and Expenditure surveys and quantified using accounting procedures. In the short-term, 49% of On-farm income was the value of household consumption while 54% of On-farm expense the value of household contributions. FGs contributed 29% to food and fuelwood self-sufficiency, generated the highest profit, were the most financially efficient land use, and average FG profit (Current assets) was greater than enterprise profit. In the long-term, FGs had the highest number of timber and fuelwood species (biological assets). Their average net realisable value (NRV) was 90% of total NRV for biological assets from all land uses. Since FGs occupied 68% of the study area, their substantial biological and land assets had high Non-Current asset values. Average FG Non-Current asset values accounted for 79% of Total Equity and were farmers' core ownership interest in enterprises. Forest gardens increase the financial viability of farming enterprises. Their financial contributions warrant recognition in national economic performance assessments.