You are correct, trees are bound by space and time, but the creator of the trees is not.
God clearly created trees with seeds in them according to their kinds. So yeah, He could create something of age, just like He did with Adam and Eve. I mean, who would have changed their diapers? It's clearly in the Scripture and not an opinion.
Gen 1: 9 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.12 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.