www.PondMegastore.com pot a waterlily, repot an over crowded waterlily, divide a waterlily. Rhizomes grow in straight lines so point the growth tip in a direction to grow across a pot. When it reaches that side of the pot. It is time to repot it again. Some hardy lilies grow rapidly others are slower. N. Wanvisa (as in video), N. mexicana are two fast types of growing lilies. Do not cover the crown of the plant with stones, common practice with new water gardeners.