Hardy water lilies reproduce vegetatively and they are fast growers. These characteristics make division a key tool for propagation and also to prevent plant overcrowding. Hardy water lilies should be lifted from the water and divided in the spring every few years to maintain a healthy form. Preventing the plant from drying out during division and using scrupulously clean tools are keys to a successful division and healthy plants.
Pull the water lily plant pot from the water, setting the pot on its side, and gently pull the plant out of the pot.
Cut the water lily rhizome into smaller pieces, ensuring that there is root growth attached on each new division of rhizome.
Plant each division into a plastic pot filled with heavy clay soil.
Drive in one or more slow-release aquatic fertilizer tablets into the planting soil for each division. Follow the product label directions for the appropriate number of tablets for the size of your division and where to place them in the soil.
Cover the clay planting soil with at least one inch of gravel to hold the soil in place and help anchor the pot.