Yes roots will go horizontal. No different as in nature if you plant a bush in your yard that has 18" of soil and then a layer of flatrock, the roots will grow down until they hit rock and then go in the direction of least resistance. Depth is still a critical key in stability though, so if you are going to grow tall you might want more depth.
tinytoon Reviewed by tinytoon on . Pot size/ shape how deep do mj roots need to be to be stable when grown in soil? Example: To use a pot that was wider than the depth to save space, will the roots grow horizontal once they hit the bottom, does anyone have any ideas if it would work just as well as a normal 3-7gal pot Rating: 5