Middle English word grene comes from Proto-Indo-European *gʰreh₁-, and later Proto-Germanic *grōaną ((plant) to grow. To green.)

Detailed word origin of grene

Dictionary entry	Language	Definition
*gʰreh₁-	Proto-Indo-European (ine-pro)	to grow
*grōaną	Proto-Germanic (gem-pro)	(plant) to grow. To green.
*gʰrōni-	Proto-Indo-European (ine-pro)
*grōniz	Proto-Germanic (gem-pro)	Green.
grēne	Old English (ang)
grene	Middle English (enm)	Green.

Words with the same origin as grene