The timber scarcity in the Philippines has created a market demand that is providing incentive for upland farmers to plant timber species either in all-tree stands or intercropped with annual vegetables. This paper assesses the role this volunteer tree planting may have in meeting national tree-planting goals. A study in Lantapan, Bukidnon Province applied a bioeconomic model to compare the viability of annual crops and timber crops and intercropped systems. The results suggest tree crops yield higher returns when there are constraints on fertility, labor and capital, and that intercropped systems generate higher annual returns than mono-cropped systems. The authors conclude that upland agroforestry should be encouraged through disseminating information on best management practices and removing inhibitors such as harvest restrictions and insecure land tenure. They support redirecting funds for public planting of fast-growing trees toward protecting complex forests.