How often should water lilies be divided? It is recommended to split lilies once every two years.
​Step 1: Have your aquatic planting containers ready (the bigger the better, should be a minimum of a 10" diameter pot, shallow pots are better than deeper ones – 6 to 10 inches deep). Fill each pot about 1/2 full with clay soil. If the pot has holes bigger than? inch fill holes with rocks to block clay from washing out into pond.?

Step 2: Space 3 Jobs tomato spikes evenly around pot or any 8-24-8 spike (could use 1 large bush or rose stake. Cover stakes with 1 inch of clay soil.

Step 3: Start by removing the plant from the pot and rinsing away the soil so you can see the rhizome. Do not let plant dry out.

​Step 4: Locate direction of growth of rhizome. Rhizome's grow horizontally and new growth has the leaves coming out and roots. Cut off old rhizome growth (with a sharp knife or shovel) where there are no roots or leaves coming out and throw away.

Step 5: Divide rhizome into lengths that match the total number of pots you will be replanting in. Locate where leaf growth and roots are. Separate each section with a sharp knife making sure there are roots and leaves in each section. Do not allow any one section to to be longer than 4 inches or you will be splitting your lily again before the end of the season.

​Step 6: Place the rhizome horizontally, roots down, with the cut edge against one edge of the pot and pointing towards the center of the pot. While holding the rhizome, fill around the rhizome with more clay soil and pack snugly, making sure you do not cover the growing top of the lily rhizome. The objective is to have 2 inches remaining to the top of the pot at this point.

​Step 7: Top with 2 inches of sand (for goldfish) or pea gravel, top with 2 inches of rock for koi. Add a little water to saturate the soil, this will keep sediment down when pot goes back into pond.

Step 8: Return pot back to pond, but keep top of pot no more than 12 inches from water surface until it is established, usually 4 weeks.

​To keep lily growing healthy and to encourage flowering add fertilizer stakes every 2 to 4 weeks. Make sure to cover stake with 2 inches of soil and pack it or you will be feeding algae.