A high quality of seedlings produced in the nurseries is based on several criteria, which are quality seeds, proper seed germination, regular weeding after germination, watering during dry periods and protection of the young seedlings from strong radiation and pests and diseases.
The seedlings remain in the tree nursery for 3-4 months and are transported to the planting site with a height of 30-40 cm. Seedlings with a bad quality (damaged, slow growth, etc.) should not be used for planting.
In Kalimantan, fast-growing species, such as Sengon (Paraserianthes falcataria) are planted during the rainy season, from December to February. As tree growth performance correlates strongly with soil fertility, on heavily degraded soils, additional organic fertilizers have to be added into the planting holes. Seedlings are planted on a 3 x 3 m spacing, which leaves enough space for intercropping with vegetables and other cash crops. 1-2 thinning activities are conducted until a density of 300 trees/ha is reached, and thus about 60 % of the trees are removed.