I do not have alot of Experience with Cannibus, but I have alot of gardening experience. Geotropisms (Hormone that reads Gravity) only seem to effect the plant at Germination, Once the Plant breaks through the ground Phototropisms (Hormone that reads Light) take effect. The Roots tend to use Hydrotropisms (Hormones that read Water) to figure out where they want to go. I have grown many different plants in many different directions to test the theorys, including one plant I grow upside down. The only time you can not get the plant to grow upside down is at Germination. Leaves and stems will chase light, Roots will chase water. This may not apply to all Vascular photosynthesis species.