Before, on the third day, while man was created on the sixth day.
Genesis 1:11-12, 26-27
11 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.
26 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.27 So God created man in his own image, in the image of God created he him; male and female created he them.
Trees created before man.
Genesis 2:4-9 7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.8 And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed.9 And out of the ground made the LORD God to grow every tree that is pleasant to the sight, and good for food; the tree of life also in the midst of the garden, and the tree of knowledge of good and evil.
Trees created after he created man. Not too good as a scientific document.