The sign for garden is a compound sign, looking like several plants sprouting out of the ground. Your non-dominant arm will form the ground, the forearm lying flat with your fingers curled as if holding a small pot, and it will come up through the non-dominant hand, opening up your fingers as the plant passes the top of your non-dominant fist. Repeat the same sign for plant or grow, but 2-3 times more.
If you have a yard with a garden, use the garden sign when you go outside. Teaching your baby this sign will help her to tell you when she is feeling like playing outside.
Teach this sign along with the other flash cards pertaining to plants, grass, and other natural elements, which helps children contextualize the concept.