Plant the rhizomes of the yellow water lilies in containers with just enough soil to cover them. Place the containers 6 to 8 inches below the water surface at the start until the appearance of new leaves. After foliage has started to grow move container to water 18 to 24 inches deep.
Yellow water lilies are a day-blooming lily variety with a free-flowering habit. The cuplike, 3- to 4 1/2-inch-wide flowers are a deep yellow color and have a sweet fragrance. The new foliage is olive green in color with shades of purple or reddish brown.
Yellow water lilies are highly invasive in nature and can easily take over natural ponds. Container planting in a concrete or lined pond is recommended to keep plant growth in check. The flowers are hardy in U.S. Department of Agriculture plant hardiness zones 6 to 10 and semi-hardy in zones 3 to 5.