“The earth brought forth vegetation, plants yielding seed after their kind, and trees bearing fruit with seed in them, after their kind; and God saw that it was good.” (Genesis 1:12, NASB)
The earth, plants and trees all immediately obey our God. Each occurs just as described in the previous verse. The vegetation, plants and trees all come forth, with their seed and fruit. It is interesting to note that we cannot assume only dry land is populated. The sea must have also been included. This stage of creation is declared good by God. The vegetation, plants and trees are all created in order to sustain life (Genesis 1:29-30), which is what God is working toward.