Although fall is a beautiful season, it can be bittersweet for water gardeners. Cold weather is on its way and that means it’s time to bid farewell to your finned friends and beautiful waterlilies for a few months. Putting the pond to bed for winter involves a few small tasks, and one of those is preparing your pond plants for snow and ice.
When fall arrives, waterlilies stop producing leaves that grow to the surface of the pond and start producing leaves that grow only a few inches high.
1. Overwinter hardy lilies by trimming off the mature leaves a few inches above the crown and dropping the pot to the lowest depth of your pond.
2. If your waterlilies are permanently planted in pockets at the bottom of the pond, all you need to do is remove the dead foliage. Hardy waterlilies need to have a period of dormancy which is onset by cold water, so do not bring them into a heated indoor pond to keep them growing.
3. Tropical waterlilies will flower up to and past the first light frost as they have no idea what winter is and no need to prepare for it. Overwinter tropical lilies inside in water over 50 degrees Fahrenheit or remove it from the pot and store in moist sand. The war water method isn’t practical for most people, and success with the most sand method is variable, often ending in the loss of the tuber to mold or rot. Botanical gardens with trained horticulturists expect to lose many of the tropical waterlilies they store every winter. The best approach is to treat tropical lilies like your annual plants that you replace every year.
4. Hardy marginals can be overwintered right where they are growing in the pond. Simply trim the foliage back leaving as much as a foot of growth above the crown of the plant. This remaining foliage provides insulation from cold, wind, and hard freezes. If the plant grows less than 12 inches tall, do not trim the foliage at all. Grass-type pond plants don’t need to be cut back at all and will provide aesthetic interest to the pond during the winter months. In the spring, remove all the dead foliage of marginals and grasses once new growth appears.
5. Tropical marginal plants should be removed from the pond and overwintered in the house as a houseplant. Another option is to overwinter them in an unheated basement or a garage that does not freeze. To do this, allow the marginal pond plant to dry until the soil is only slightly moist and store it that way all winter. You can return the plant to the pond when the water temperature is over 50 degrees Fahrenheit. In warmer regions, tropical plants can be buried in the soil around the pond to overwinter, then simply dug up and replanted in the spring.
Whether or not you decide to over-winter your pond plants is up to you. Some people enjoy buying new varieties each pond season, while others prefer to preserve existing plants. Either way, enjoy the beauty and therapy that water gardening with aquatic plants brings to your life!