A first machine of a tree planting system includes: a cultivator cultivating soil where a plant for tree planting is to be planted； a first traveling device traveling with the cultivator； and a cultivated position detector obtaining and outputting actual cultivated positions corresponding to positions of the cultivator while the cultivator travels with the first traveling device and cultivates the soil. A management device of the tree planting system stores actual cultivated positions. A second machine of the tree planting system includes: a planting device planting a plant in the soil； a second traveling device traveling with the planting device； a planting device position detector obtaining a position of the planting device； and a controller controlling a position of the planting device based on: actual cultivated positions acquired from the management device； and the position of the planting device at the timing when a plant is planted.
