You can use selected seeds and sow them. In areas with plants, there is always a seed stick in the soil. If you use the top soil from around the Growboxx® while planting, and fill the seed pockets with it, this seed will germinate automatically and you get plants that fit there within the ecosystem. if you only want to plant a tree and don't want seed to germinate in the seed pockets, then take soil from deeper in the ground, it has less seeds.