Choosing Aquatic Plants
fragrance of a water lily blossom, the contrast of variegated
foliage, the filtration qualities of Water Hyacinth;
these are just the beginning of the benefits of plants in your
water garden. To many, aquatic plants are the highlight of their
garden. But, I am often asked about selecting the right plants.
plants have many functions in the water garden. The obvious
is that they provide beauty. The foliage and flowers offer the
finishing touches to complete a dazzling aquatic display.
with an understanding of filtration know the nitrification cycle
and how plants play their role. Fish naturally secrete ammonia
into the pond water. Biological filtration works to convert the
ammonia into nitrites then the nitrites into nitrates. The nitrates
are then used by the plants. If there are not enough plants using
up the nitrates in your pond, you end up with an algae bloom (in
extreme cases of nitrate buildup the fish may suffer as well).
Plants that cover the pond surface also reduce algae by limiting
the amount of sunlight reaching the water. For the best balance
in a water garden around 2/3 of the pond surface should be covered
with plant foliage.
often overlooked, use of plants in the pond is protecting your
fish from hungry predators. Whether it is tall plants at the water's
edge that help prevent a raccoon from reaching the pond or the
water lily pads covering the surface that give the fish a place
to hide from a heron, a few plants may be all that is needed to
avoid making a meal out of your pet fish.
it comes to actually selecting the plants for your pond, there
is nothing more important than your eyes. That's right, while
there are certain types of plants that you may want as we will
discuss in a moment, choosing plants that you think look good
is the most effective way to get a water garden to be proud of.
Lotus leaves grow atop stems that are attached to the tuber in
the soil (the first leaves of spring will float on the surface
like water lily leaves). The leaves can be 12- 24" in diameter
and 2 - 5' above the water. The flowers, which appear generally
June through August come in variations of white, yellow, and pink.
When the flower has finished it leaves a brown seed pod. These
are commonly used in dried flower arrangements. The Water Garden
sells Lotus at our retail store, but due to the extra care and
sensitive nature of lotus tubers we do not ship this plant. Lotus
are generally hardy to USDA zone 5 and prefer full sun.
WATER LILIES: Lily pads rest on the water surface
(when crowded some pads rise slightly above the water). They are
attached to the rhizome via long stems. In hardy lilies these
pads are mostly all green, some varieties have light mottling
and new leaves of many hybrids emerge with a red color. The flowers,
which appear in summer, also float on the surface, some hybrids
have flowers that will rise a few inches above the water. Flower
colors in hardy lilies include white, yellow, pink, peach, red,
and variations of each. Hardy lilies go dormant in the winter
and return in the spring provided that the rhizome did not freeze.
Hardy lilies generally do best when placed with the crown of the
plant around 12" below the water's surface.
WATER LILIES: Tropical water lilies offer some characteristics
not available in hardy varieties. Blue flowers and purple flowers
are only an option with tropical water lilies. There are also
night-blooming varieties. The flowers on these open around dusk
and stay open until mid-morning. The flowers of tropical water
lilies rise several inches above the surface of the water. They
are also more prolific and more fragrant. Tropical lilies need
water temperatures in the 70s, so they cannot go out in spring
as early as their hardy cousins. While they will not survive outdoors
except in very limited warm areas of the country, their benefits
still make them worth a try in most water gardens. Just because
they don't survive your winter does not make them unsuitable as
an annual plant to have just for the season. Tropical water lilies
don't like to be quite as deep as hardies, having the crown 8-10"
below the water surface is great.
PLANTS: Often called "marginal plants",
these plants are typically placed in more shallow areas of the
pond. Most ponds are built with a plant shelf at around 12"
deep specifically for placing shallow-water plants. There are
hundreds of varieties of plants that go in this group. Looking
at sun requirements and growing height will help you choose the
right plants for your pond. But, again, please don't underestimate
your own preference. Pick the plants you like and you are bound
to be happy with the decision. There are shallow-water plants
that will survive anywhere in the country and those that will
survive in only limited areas. Just like tropical lilies, a plant
that doesn't survive the winter can still make a wonderful choice
to keep for one season.
PLANTS: As you might gather from the name, these
plants grow in a similar fashion to water lilies. That is that
they are rooted in soil, with leaves floating on the water surface
attached to the roots with a long stem. These are also a great
way to get some surface coverage without a lily. Some, like 4-Leaf
Clover, tolerate very low-light conditions and thus make a good
alternative when a lily is not the right choice.
PLANTS: Floating plants are simply plants that free-float
and do not need to be anchored in a pot. It doesn't get much easier
than that. Floaters are generally very prolific. Many states are
beginning to ban these as they become problems in natural waterways.
Responsible water gardening includes keeping plants contained
within the water garden. If your state allows these plants, they
are extremely beneficial to the pond. They not only shade the
surface, but with their roots hanging in the water, they pull
a great deal of nutrient from the water reducing algae growth.
PLANTS: Underwater grasses are the staple of the
backyard pond. The most common is Anacharis.
These plants grow completely submerged (although the growth of
most will end up reaching the surface). We place these in pots
of pea gravel to hold them in place. This keeps them anchored
and keeps the pond looking neater. These plants are an excellent
way to remove nutrients from the water.
Placing Aquatic Plants
have finally chosen the plants to complete your water garden.
Now you need to determine where to place them and how to get the
most aesthetic benefit from what you have. When doing this, it
is important to remember that plants grow. This means you want
to plant them in large pots to give them room to spread out. It also means you may not need
quite as many plants as you think (unless you give in to instant
gratification). Try to picture how the plants will look once established
while planning the layout in the pond.
most ponds, you have one main area that the pond is enjoyed from.
Think about this as you are placing your plants. Don't place a
4' tall cattail in front of a low-growing Water
about the moving water. Water lilies, in particular, do not tolerate
a direct splash and do best in an area of the pond with less movement.
be afraid to experiment. There is nothing that says each pot can
only have one type of plant in it. Place multiple types of shallow-water
plants in the same pot for a new look. And vice-versa, just because
you have room for 6 shallow water plants, doesn't mean you need
6 different varieties. Try 3 of one and 3 of another. Then you
decide if you want to group the like kinds or alternate.
themes can be a fun way to make your pond standout. Maybe you
want only plants with variegated leaves. Or, perhaps you only
want plants with red flowers.
your pond has been planted, your plants just need a little basic
care to provide you with everything you had hoped for. Trim off
foliage as it yellows or browns, fertilize on a regular basis, and divide plants that are getting too large
for their pot.
While, we have given some suggestions on how to choose some plants,
remember that this is your pond and you can't go too wrong. So,
give it your personal touch by choosing plants that you will enjoy
See our article on plants that grow well in shady areas for more information.