SB 6.4.6
tabhyam nirdahyamanams tan
upalabhya kurudvaha
rajovaca mahan somo
manyum prasamayann iva
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My dear King Pariksit, when Soma, the king of the trees and predominating deity of the moon, saw the fire and wind burning all the trees to ashes, he felt great sympathy because he is the maintainer of all herbs and trees. To appease the anger of the Pracetas, Soma spoke as follows.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
It is understood from this verse that the predominating deity of the moon is the maintainer of all the trees and plants throughout the universe. It is due to the moonshine that trees and plants grow very luxuriantly. Therefore how can we accept the so-called scientists whose moon expeditions have informed us that there are no trees or vegetation on the moon? Srila Visvanatha Cakravarti Thakura says, somo vrksadhisthata sa eva vrksanam raja: Soma, the predominating deity of the moon, is the king of all vegetation. How can we believe that the maintainer of vegetation has no vegetation on his own planet?