The water lily is one of the easiest aquatic plants to divide and transplant. Add an assortment of water lilies that bloom in the daytime and at night to lure dragonflies and other aquatic wildlife to your pond. Follow these tips to help your hardy water lilies spread and thrive in your backyard pond.
Step 1 - Recognize That Your Water Lily is Ready to be Divided
Hardy water lilies grow quickly and spread in abundance. Divide and transplant them every 2 to 3 years. Watch for roots swarming around the pond, a split pot, or reduced blooming, signifying the water lily is root-bound. Tropical water lilies will need dividing when blooming ceases in very warm weather.
Step 2 - Divide at the Root
To divide, lift the water lily and its pot completely out of the pond. Then find the rhizome, the water lily's thick horizontal root. Rinse it gently with your garden hose, on a spray setting. Next, find some crowns on the rhizome, each showing where a new lily pad group will sprout. Cut between the crowns with a sharp knife. Each segment can become a new water lily plant. Slice off and compost any mushy or decomposing sections. Share any extra water lily rhizomes you have. Avoid overcrowding your pond with these aquatic plants.
Step 3 - Plant the Rhizome Sections
Use a large shallow pot to plant the new sections. A car oil change pan is just the right shape and size. Give the new sections room to expand: put each in its own pan. Water lilies bloom most abundantly when divided as seldom as possible. Topsoil is suitable, but a soil with high clay content is best. You can even use a bargain cat litter that is free of special odor and clumping additives. Lay each rhizome section in a separate pan and cover with soil. Top with gravel to prevent the soil dispersing into the pond water. Place the shallow pans at the bottom of the pond, at least 18 inches below the surface of the water.
Step 4 - Improve Pond Fertility
Water lilies in ponds with fish will self-fertilize from the fish waste. In ponds without fish, add fertilizer sparingly to avoid encouraging algae growth. Use aquatic tabs inserted into the soil to fertilize once a month. Provide your pond with 6 to 10 hours of sunlight daily.
Step 5 - Tropical Water Lily - Separate New Growth from the Main Tuber and Plant
Lift the tropical water lily's pot out of the pond. Carefully extract the whole plant and its tuber. Rinse the tuber with your garden hose. Check the tuber for short runners, and choose one that has formed a new tuber. Cut the runner about one inch away from the top of the new tuber. Plant this tuber in its own tall pot, with clay soil and a layer of small pebbles on top. Do this in midsummer, when the water lily has spread noticeably. Remove tropical water lilies from the pond when nighttime temperatures fall below 50 degrees F (10C). Store the tubers for next spring.