Hardy water lilies, if grown in containers, require division every year or two. Overgrown lilies in need of dividing do not bloom. They produce smaller and smaller leaves from multiple growing points in the rootstock. The plant has a congested appearance and leaf color may be yellowish. The lily’s container may be so full of roots that it is difficult to insert Lilytabs fertilizer tablets. Division usually restores vigor and bloom. The best time to divide a hardy water lily is in the spring. They may be divided at other times of the growing season but usually will not bloom for three to four weeks afterward. Many water gardeners divide and repot their lilies every spring when they clean their pond.
- Remove the waterlilies from the container and rinse off all soil. The plant will have a main growing tip and some secondary juvenile growing tips visible on a large rootstock.
- Cut off (or break off) old rootstock end, leaving 4-6” of healthy rootstock with the main growing tip. Cut off juvenile crowns. Discard old wood rootstock end.
- Repot trimmed rootstock, following planting instructions below. Use clay soil from your garden. Be sure to fertilize with tablets made especially for water lilies and other water plants. Juvenile crowns or growing tips may be discarded or potted in a small (1-gallon flower pot) container and grown in shallow water for a season. They will be blooming size plants in one year or less.
- Fill container 1/3 full with soil.
- Push in Lilytabs, as per their instructions.
- Cover with until container is ½ full.
- Position lily.
- Gently add soil around roots and tamp down.
- Keep growing crown (at top of root formation) free of soil.
- Thoroughly saturate the soil with water.
- Cover soil with ½” of pea gravel, still keeping the crown free.
- Lower potted lily into water container or pool, lowering it into the water just enough to keep a few inches of water above the leaves.
- Lilies require 2-3 weeks adjustment after planting before new growth resumes.
- Waterlilies should be fertilized once a month during the growing season.