Lotuses (Nelumbo spp.) are aquatic plants desired by water gardeners for their attractive white, pink, red and yellow flowers. The plants are grown in U.S. Department of Agriculture plant hardiness zones 4 through 10, but need protection when water temperatures drop blow 50 degrees Fahrenheit. It's best not to disturb the roots of this delicate plant needlessly, so plan to divide your lotus when it's time to transplant. Replant large lotuses every two to three years; repot a bowl lotus annually. Do the work in early spring when the plant is dormant, before new growth begins.
Remove the lotus pot from the pond or winter storage and carefully turn it upside down to remove the plant from the container. Leave the lotus inverted, and gently wash away the excess soil with a garden hose so you can easily see the root system, which resembles sausage links. Portions of the root that look like sausages are known as “nodes” or “tubers,” while the small links between them are called “internodes.”
Select a healthy node that is firm and white for division. The end of the tuber you choose should be pointed and should curve slightly upward -- this is the growth tip where the new plant will form. Follow the lotus root back from this growth tip, and cut it from the rest of the plant at one of the internodes. Leave two or three nodes on the piece you cut. When you are done, you should be holding a section of root that includes a growing tip and at least two and one-half sausage links.
Place one-half inch of sand in the bottom of a round container without drainage holes on the bottom. Fill the container one-half to three-quarters full with your favorite aquatic potting mix. Aquatic plants do best in heavy clay loam soils, and should never be planted in traditional potting soil.
Add water to the potting mix until the soil becomes muddy. You want the soil to be wet, but not soupy. It should be damp enough to make mud pies, and not so wet that the pies won’t hold their shape.
Lay your newly divided tubers in the container, with the growing tips pointed upwards. Gently cover them with soil, covering the thickest part of the tuber with 2 inches of soil but leaving the points of the growth tips uncovered. Add another inch of sand to the top of the container, again making sure you do not cover the points of the growth tips. Cover the soil in the pot with three-quarters of an inch of pea gravel if you have fish in your pond, to keep them from picking at the new plant.
Repot the parent plant from which you took your divisions. Place both the parent plant and the new plants in your pond or water feature. Place the established parent plant with the soil surface 8 to 12 inches below the water’s surface, while new divisions should be only 3 to 4 inches below the surface. Tip the pots as you place them in the water, so they fill slowly without disturbing the newly planted tuber.