With CO₂ now exceeding 400ppm, strategies for effective carbon sequestration and long-term storage are urgently needed. Deforestation in the tropics is one of the largest anthropogenic sources of atmospheric CO₂. Nonetheless, tropical forests still store large amount of CO₂, and encouraging forest succession in previously deforested areas is considered a promising strategy for sequestering carbon. Secondary forests are dominated by fast-growing species with low wood density, which store less carbon than slower-growing, late successional species. However, some tropical tree species with high wood density have relatively fast growth. By using these species, plantations could be an effective strategy for carbon sequestration. We conducted an experiment using two faster-growing, high wood density native species. We tested whether using these species will significantly enhance aboveground biomass (AGB) compared to control plots in secondary forest in Panama. Six years after planting, many planted trees grew to 10+ m tall in plantation plots, which provided shade that suppressed the grasses. In the control plots, grasses still dominated. Although there was no difference in species richness/diversity or number of recruited plants between plots, plantation plots had substantially higher AGB compared to control plots. Without shading from our focal species, grasses will keep dominating the land for years with little increase in AGB. By using native species that are high wood density and faster-growing as in our study, we could foster a system to manage secondary forest succession to increase long-term carbon storage.