Temperatures are dipping and the days
are shortening. As you say goodbye to the long sunny days of
summer, it's time to turn your attention to the plants in
and around your pond to make sure they're ready to face the
first frost
Hardy Marginals
As with terrestrial,
perennial plants, dropping temperatures alert your hardy
aquatic plants to prepare for their winter dormancy. You
should stop fertilizing them as you see leaves begin to
yellow and brown. It's ok to leave these plants where they
are in your pond to weather the cold of winter, just be sure
to trim the dying foliage of your marginal plants down to 2"
above the water level. Remove any excess plant material as
needed.
Tropical Marginals
Water gardeners who
live in our colder zones will need to treat these plants as
they would any garden annual by replacing them each season.
A fun alternative is to treat them as tropical houseplants
and bring them in for the winter. Most tropical marginals
will do well potted in heavy garden soil in a sealed clay
pot with no drainage holes. When kept wet, the plants do
well in a sunny window or sunroom. Come springtime, you can
replant them back in the pond and see what happens.
Water Lilies
Water lilies will also begin to show
their dislike for the cold with yellowing leaves and fewer
flowers. Trim off the mature leaves a few inches above the
crown and drop the pot to the lowest depth of the pond. If
your water lilies are permanently planted in pockets at the
lowest part of your pond, all you need to do is remove the
dead foliage. Hardy water lilies need to have a period of
dormancy which is onset by cold water, so do not bring then
into a heated indoor pond to keep them growing. Tropical
water lilies 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. Tropical water lilies can be over-wintered
indoors in water over 50 degrees F, or they can be taken out
of the pot and stored in moist sand. The warm water method
isn't practical for most, and success with the moist sand
method is variable, usually ending in the loss of the tuber
to mold or rot. Botanical gardens with trained
horticulturists expect to lose many of the tropical water
lilies they store every winter. Start over each year as you
do with flats of annuals.
Lotus
As with the marginals in your pond,
the foliage of your lotus plants will need to be trimmed
back after they have died back and turned brown. It's
important not to cut the leaves while they are still green
because freshly cut, hollow stems are susceptible to disease
which can then spread to the plant's tuber, possibly killing
the plant. Lotus tubers will not withstand freezing, so any
plants that are growing in the shallow areas of your pond
should be moved to the deepest part of your pond, away from
freezing water. When you take the time to care for your
aquatic plants in the fall you'll have less work ahead of
you in the spring and healthier plants will emerge from
their winter's nap.
