Most water plants are more accurately divided into how invasive they are, not if they are invasive. In a water garden setting it is very helpful to have hole-less pots for your water lily to better contain the rapid growth of many of these plants. Division and maintenance are important for maximum performance of water lilies.
At Pondibilities our large and medium lilies are potted in 10″ x 8″ hole-less pots and are fertilized every three weeks to foster maximum performance. Once they are in your pond the continued fertilization and a division every year or two is the best practice. Once the plant has jumped it s pot, the pads become crowded and/or elevated, or the blooms do not perform at their previous level it is time to divide your water lily.
Water Lily Division:
Here is an over grown water lily, it may not have jumped the pot, but this lily is ready to be divided. There are many different root types, but these basic rules apply.
Here is the same lily dumped out of the pot, cut apart, with crowns exposed. The crown, or growing point, is the tightly clustered point of stems. This crown is growing directly from the tuber that will feed it in the Spring and continue it’s growth. If the tuber has already jumped the pot or distorted the ’round’ of the container, it may be necessary to cut open the container.
All of the excess root/tuber that does not have a growing point (crown) can be cut away and trashed. It often helps to leave some old hard tuber to keep some food source and to help anchor in the planting media.
Hole-less pots that are wider than tall (we use 8″x5″) pots, filled roughly 3/4 full. Two tabs of fertilizer (per directions of Highland Rim Fertilizer) and packed soil with the cut of the crown against the side of the pot or near center. Many types of lilies grow horizontally instead of vertically.
Securely pack soil, top with pea gravel, and dampen soil before dropping into pond. Label variety and date fertilized if you want to keep close track. Depending on product used, we suggest two tablets every three weeks to a month.