Growing leeks in containers! Leeks create huge root balls, which support the growth of beautiful, tall, thick, and white leeks. If you're growing in a container though, how do you give the roots enough space while also supporting the top growth? The answer? Support with a tube of some kind. I used 1.5" PVC that I cut to 6" long and threaded through my leek transplants. This way I can plant my leeks shallow in the container, and support them above. The tubes also block out the light, which helps