Old English, present-participle adjective from grow (v.). Growing season is attested from 1729; growing pains by 1752.
late 14c., "a gradual increase, action of causing to increase," verbal noun from grow (v.). Meaning "that which has grown, a crop" is from 1540s. Dialectal growsome "tending to make things grow" is from 1570s.
the growing season for corn
good growing weather