Here it is Spring....the task begins for us water gardeners. Clean the pond, check the water, make sure pumps are working properly, tell the fish "I know you think your hungry, but I cannot feed you until the water temperatures get a little higher..." and then the task of dividing those water lilies to start new ones. It's a lot easier just to purchase new ones, those I don't have, but want.
Dividing and re-potting lilies is not a hard task, but a messy one. It is essential for their health and vitality. When a water lily grows it will eventually grow over and out of its pot. It fills the container with roots and rhizomes, displacing the soil and leaving no room to fertilize it. You can divide it and discard the old roots and rhizomes making space for the lily to renew its strength and keep flowering well.
You will know when it is time to divide a lily when it stops blooming as well and its foliage starts crowding. The leaves become smaller and more sparse. The best time to divide lilies is in the early spring, just before the lily starts to actively grow.
Take the lily out of the pot. Remove the soil by using a spray of water from a garden hose to completely wash away the soil from the rhizome. Generally, a rhizome has a main growing tip. Next select the part or parts from the rhizome that are the nicest. Cut to about three or four inches long and discard any remaining part of the rhizome left. Trim away excess roots and damaged foliage. If you aren't going to re-pot at this time keep the new plant in the shade with damp newspaper covering the plant or submerged in shallow water.
Fill your container with a clay base soil, mound against one side of the container and place the rhizome at a 45 degree angle with the cut edge against the pot and the growing point at the level of where the top of the soil will be. At this point you would want to add a couple fertilizer tablets, one on each side of the plant. You can then add more soil to within a couple of inches from the top of the container. Press the soil firmly in place and add about one inch of small pea gravel to cover the soil but keep it off the growing point of the plant. You can then gently add some water to the container and slowly lower the plant into the pond. If you place it just a few inches under the water for the first few weeks, you will get new growth faster. Then you can place the plant at your proper growing depth which is normally 12 - 20 inches of water over the top of the plant.
Continue to feed your newly planted water lily one fertilizer tablet per gallon of soil monthly and the result will be another great performing lily.