To those of us who live in the Southern part of the US, winter rarely arrives and overwintering water lilies is far from our thoughts this early in the year. Even when we do think of it our choices are two: Hope that we do not have a hard freeze and most of the time we don't, or even if we do, chances are it will not last long enough that the tropical water lilies will be lost. And even if they are, chances are a neighbor's won't be, so we can get a start. I know, I know, we are lucky, BUT you are not having to wonder how you will make it through one more day of the intense heat that August heaps on us, while knowing that September is just another name for August and October is more of the same.
So to you who have to concern yourselves with freezing weather, here are some tips for overwintering those expensive tropical lilies.
First of all stop feeding them about 6 weeks before the first frost. You have already stopped, right? Even here in New Orleans, I recommend ceasing feeding in October so the lilies will be dormant for the colder months. If we continue to feed them, chances are we will lose them even in a mild freeze because the tender new growth will be damaged.
One way to overwinter lilies is to drop the pot to the deepest part of the pond, remove the leaves and just forget them until spring. In the spring, remove them from the pond. If the corms are mushy throw them away. There should be many corms in the pot, so you will not lose your lily. Just pot up non mushy corms. Pot them up, put them back in the water and start feeding when the leaves reach the top of the water.
This method works about half of the time.
As the days shorten and the weather cools, the leaves will become smaller and smaller, turn yellow and die. When the leaves are gone or almost gone, remove it from the pond. Take it out of its pot and rinse off the soil. There will be tubers all through the soil, among and beneath the roots. They will be about the size of walnuts, hard and dark brown. If they are mushy discard them. Cut or break them apart...usually you can do this with your fingers, and put them in a warm place to dry. Let the dry for a few days.
Then get some play sand or builder's sand, dampen it and fill a resealable plastic bag with sand about halfway. Put the corm in and fill the bag the rest of the way. One corm per bag, please. If you label the bags, you will remember what they are. Seal them and store in a cool, dark place where the temperatures are between 50 and 55 degrees. When spring arrives, pot them up and feed when the leaves reach the top of the water.
This method will work about half the time.
The surest way to overwinter water liles is to buy hardy varieties. Their flowers do not shoot above the water like the tropicals and the colors will not be quite as dramatic, but they will overwinter anywhere.