Marginal plants are water plants that grow with their roots below the water and their crowns slightly submerged, leaving most of the foliage out of the water. Most marginals do best with the water 1-3 inches above the top of the pot. Flowering varieties perform best in full sun, although most will grow fine in light shade. Newly purchased marginals may need to be repotted in a little as a month, especially ones purchased in 4 1/2” pots. Plants purchased in one gallon and larger pots should be fine for the season.
Standard potting soil should not be used, as perlite and peat moss may float out of the pot once it is submerged. Instead, heavy clay soil collected from the yard actually makes a better growing medium. Avoid the upper 6”, as it may be too rich and foul the pond. Line any drainage holes of the planting container with newspaper or burlap to keep the soil in the pot. Make sure that if you use newspaper that it is printed with soy ink.