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Hardy Water Lilies and Lotus
Hardy water lilies and lotus will overwinter if their roots do not freeze solid. Foliage will die back mid to late
fall but roots will remain alive. Steps to overwinter lilies should be taken at this time. DO NOT COVER the pond
or bring plants inside until late fall when dormancy has begun.
Methods:
A.
Move containers to the deepest area of the pond. Remove dead leaves on lilies but not on lotus. It is
recommended that your pond be at least 2 1/2' to 3' deep in one area if this method is chosen. Colder zones
in Canada should increase this depth. You may cover pond with boards or framed plastic to provide extra
insulation. Do not make airtight. Return containers to original positions in spring.
OR
B.
Use this method if your pond is shallow and will likely freeze solid. Remove the old leaves from the lily and
bring planted containers indoors to cold storage, approximately 40°F (5°C), for the winter. Keep containers
moist and dark at all times. More lilies are lost from drying out than from freezing. Return plants to the pond
after the ice has melted the following spring.
Note:
Northern sections of Canada should bring plants indoors or use a pond heater just to be safe
Hardy Shallow Water Plants
Some hardy shallow water plants can tolerate being frozen solid
while others need their roots or tubers to remain in the water. Irises,
Rushes (except Pickerel Rush), Sweet Flag, Cattails, Horsetail, Marsh
Marigold, Bulrush, Houttuynia, Golden Creeping Jenny, Watercress
and Water Forget-Me-Not may be left in shallow water where they
will likely freeze. Most other varieties should be moved to deep water
or brought indoors to cold storage (See method B above). Return all
plants to growing shelves as soon as the ice has melted in the spring.
NOTE:
Do not remove dead leaf stocks from emergent plants such
as cattail and rushes until spring. This will allow the root system to
“breathe” during the winter.
Tropical Plants
May be grown outdoors during the summer, but are considered annuals unless heated greenhouse facilities are
available.
Tropical Water Lilies
When brought indoors, tropical water lilies and plants continue to grow during the winter months and must
receive sunlight and heat. Growth slows considerably in December and January when there is very little sunlight
and the leaves will become yellow and small. Most people treat tropical water lilies as annuals due to the
considerable effort required for their continual growth.
Method: Before the first heavy frost in your area, bring the tropical lily indoors to a heated greenhouse or
sunroom. Place the containers in a tank, fertilize sparingly and ensure water temperature will not fall below
21°C (70°F). This will prevent the lily from going into a dormant state even though growth slows considerably.
The following spring when the pond water temperature has warmed to a consistent 21°C (70°F), in early June,
place the lily back in your pond.
Tropical Shallow Water Plants
Like tropical water lilies, shallow water plants must continue to grow during the winter months. Growth will be
reduced considerably as daylight hours diminish. Umbrella Palm, Dwarf Papyrus, Little Giant Papyrus and White
Arum lilies will survive the winter indoors and make excellent houseplants. Other varieties are best treated as
annuals.
Method:
Remove tropical plants from the pond before the first severe frost and bring indoors to a heated
greenhouse or sunroom. Plants must remain in water and be kept at a temperature of approximately 18°C
(65°F). Remove old growth if it yellows. Return to the pond in spring when there is no risk of frost.
Note:
Small amounts of fertilizer may be required to encourage plants to keep growing during the winter.
(continued on page 42)
OVERWINTERING YOUR PLANTS
cont’d
2013 Photo Contest – Alana Palm
