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The Care of
Tropical and Semi-Tropical Terrestrial Utricularia,
Bladderworts ã 2003
By Karen
Oudean
The
word Utricularia comes from Latin. It
means little bag or sac. This is a
good description of the bladderwort’s traps. They look like tiny plastic bubbles ¼ ” or smaller in
size. They open with great speed,
in as small a time frame as 1/460 of a second.
The traps work like the bulb of a turkey baster or eyedropper.
Water is removed from the bladder shaped traps by internal glands that
excrete it. After the trap is empty
of water, it is ready to spring open again when the trigger hairs are touched.
Like a vacuum, it sucks in its prey and the flexible hinged door shuts
tight. The door is hinged only one
way to avoid the escape of a tasty meal. It
usually takes only 15-45 minutes for the traps to reset themselves.
Tiny creatures are captured, then digested by enzymes made by the plant
and by bacterial action. If you use a magnifying glass of 2 X or a microscope of up to
30X you can see the traps in detail. The
traps of terrestrial bladderworts grow in soil. To observe them, plant them in a clear glass or plastic
container and cover the sides of the container with black plastic.
The traps will grow against the sides of the pot or bowl.
When the carpet of little grass like leaves extends to the edge of the
pot, remove the black plastic and you will be able to see the traps.
Replace the plastic if you want the traps to continue to grow next to the
container’s sides. Some of the
bladderworts, such as U.livida and U.sandersonii, bloom for 6-8
months. Most bloom for 1 or 2
months, once or twice a year. The
flowers have long spurs, lipped corollas and calyxes.
Their colors range in shades of white, purple, blue, red and yellow.
Plant these fascinating critters with your indoor carnivorous plants to
control fungus gnats and microscopic organisms.
Warm
climate bladderworts are fun and easy to grow.
Their requirements are few. (U.
bisquamata, U. cornuta, U. livida, U. pubescens, U. sandersonii, U. dichotoma.)
1.Light
requirement:
A.
Indoor
Culture: Any windowsill other than one that faces N or NW will do.
If the sun burns the leaves during the hottest part of the day, a lace or
sheer curtain is the perfect filter. If
you have no suitable window a 23W compact fluorescent plant light in a desk lamp
or two 32W fluorescent tubes in a shop light should be placed 6” to 8” above
the plants leaves. Use fluorescent
plant lights in a terrarium. Incandescent
or halogen lights get to hot. Baked
bladderworts anyone?
B.
Summer
Patio Culture: Place the plants in light or filtered shade all day.
Temperatures need to be above 45° F at night.
2.
Temperature requirement:
Summer: 50°F to 95°F
Winter: 45°F to 70°F
3.
Water requirements:
A.
Indoor and Outdoor Culture: This is a bog plant.
These bladderworts like a high
water table, ½” to 1” below the top of the pot, summer and winter.
Place the plants in bowls or trays of water that are deep enough to
provide this level. They will
tolerate lower water tables if they are used in mixed plantings of carnivorous
plants, but tolerate does not mean thrive.
Keep a stock container at the proper water level just for backup. Use
distilled or rain water if your tap water is high in iron, calcium or other
minerals.
4.Potting
Instructions:
A.
Repotting is easy and can be done any time of year if the plants are
actively growing. Use peat moss by
itself or with equal parts clean sand or super fine perlite. Do not use sand from sources contaminated by salt water.
Use sand from creek or riverbeds where ground water tests acid pH 4-6.5
with an aquarium water test kit. Mix
soil well and fill your container. 21/2”-4”
plastic pots are fine. Cut the
bladderwort turf with a sharp knife into pieces that are at least 1”
square. Place these plugs into
depressions made in the potting medium in the new pots or put the whole plant
into a larger pot of planting medium. Water
from above to settle the soil and the plants.
Place the pots in a water tray or bowl and add enough water to bring the
level up to ½” to 1” from the top of the soil. When the plants fill the
container completely, it is time to repot.
They keep growing outward from the center and the outside edges.
They will not put up with being root bound for more then a few months.
Bladderworts can be used as an annual groundcover in outdoor containers of hardy
bog plants. In early summer just add one or more plugs of bladderwort turf to
your outdoor bog.
B.
A week or so after potting, you may want to start misting the leaves with
¼ strength orchid(no urea) once a month during the growing season.
I have not found it necessary so far.
For
more information:
There is an excellent TIME/LIFE videotape at most public libraries entitled “Death Trap”. Timber Press carries the book “Carnivorous Plants of the World” by Pietropaolo and Pietropaolo. Donald E. Schnell’s book “Carnivorous Plants of the United States and Canada” is also very informative. “The Savage Garden” is a great new book by Peter D’Amato.