Overwintering tropical waterlilies is a different kind of gardening activity. You can do it if you follow a few simple rules.
Remove Roots From The Pots
Before the first frost, remove the roots from the pots.
Trim off most of the leaves and roots so the roots will fit into a one gallon (roughly six inch) pot.
Repot in fresh soil.
Repot in fresh soil – heavy clay from your garden is perfect. Potting soil is too light and a great deal of it will float (perlite, bark etc)
Waterlily ‘Barbara Dobbins’
Put In Warm Water
Put in aquarium where the water temperature is never allowed to go below 68F
Use Grow Lights
Direct grow light lighting kept no more than six inches above the water line. Usually we’re looking for several hundred watts. In other words, at least two large bulbs or grow lamp tubes.
If They Don’t Grow Leaves But Form Tubers Instead
If the tropical water lilies do not grow but instead form walnut sized tubers, you can remove the tubers and store in water that goes no lower than 55 to 60 F for the winter.
Use an aquarium heater and thermometer to heat and monitor the water temp.
Alternately, you can keep them in wet vermiculite at these temperatures until spring.
When placed in small pots in the spring and installed in 72F water, they will (hopefully) 🙂 start to grow again.
Grow for at least one month in gallon pot before putting out into pond.