As many of you out there in gardenland know, now is the time to get those tender tropical plants indoors for the winter. One of the great tropical plants in my summer routine which I have been meaning to write about are water lilies. Water lilies are known botanically as Nymphaea, and are found really all over the world: Australia to Asia, Africa, here in North America, and on and on.
These kinds of aquatic plants have roots that grow in soil under the water, and have to be anchored in and fertilized through the summer months when they are most active. Usually the soil is a dense clay and you top your containers with pebbles or stones, being sure to avoid covering the crown of the plant.
There are hardy species of water lilies out there that can go as cold as a Zone 3, but most of the ones you find at retailers are the tropical species and hybrids. For your all your plant buying be sure to make an effort to know the plant's cold hardiness. The USDA created a hardiness zone map that can be the most helpful when learning about plants and horticulture and especially when experimenting with tropicals in our temperate climate. It can help to show you the natural range for a plant, which then can help you figure out how to provide it with the best environment to thrive in your garden. To see what the USDA hardiness zone map looks like, and to bookmark it for yourself for the future, click here. Obviously with climate change and global warming zones are shifting and exceptions are present, but it is still an invaluable guideline as a gardener.
Most tropical Nymphaea are hardy to zones 11-12 which means they would be happily growing all the way down in southern Mexico. Tropical water lilies like a summer water temp between 65-70 degrees Fahrenheit (at least!), and in order to over-winter want a winter water temp around 50 degrees. They really need exposure to full sun in order to do well, and placid water is a must. Potting and placing aquatic plants in a water feature can be really fun and easy and provide a great twist to your summer. Of course if I had/when I have a yard big enough to have a pond I would like to experiment with both the hardy species and the intriguing might-blooming tropical Nymphaea that are out there.
And mind you, these are not lotus, which are aquatic plants in the genus Nelumbo. Some people seem to confuse the two but they are really very different plants. Water lilies grow their foliage (lily pads) on the water's surface where lotus leaves sit above the water. The same goes for the flowers, with lilies much closer to the water's surface if not on it, and lotus flowers are much more upright. This is a lotus up at the New York Botanical Garden from back when I was a student in 2005. Anyway, I'm babbling.
This is a tropical day-blooming hybrid water lily. They are on their way out now, and didn't get as much sun as last year, but still strike me as being so beautiful.