To sign plant or grow, take your non-dominant hand to form the pot by making the ASL sign for 'C', only it is lying down on its side. Then take your dominant hand, forming a flat letter O sign by making all your fingers touch, have it come up through the non-dominant hand's "pot" bottom, and finally open up your fingers as the "plant" passes the top of your non-dominant fist, looking like leaves opening up or a flower blooming.
If you have a yard with a garden, a window box with plants, or even just indoor, potted plants, use the plant sign to teach your baby. Teach your baby an appreciation for these living things so that they grow up seeing the beauty and function of plants in our daily lives.
Spend as much time with your kids outdoors. Help them plant a vegetable, fruit, or flower garden.