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From
Seed to Autumn Gala and Beyond:
Victoria
Water
Platters at the U.S. National Arboretum
The enormous
leaves and unusual flowers of the Victoria water platters were a
big hit this summer at the U.S. National Arboretum. The hotter than
normal weather made them grow especially well this year. For the
first time, we grew all the Victoria water platters displayed in
our aquatic garden from seed. We successfully grew enough plants to place
sixteen in our pool and also distributed others to horticultural institutions
across the country. These tropical wonders need special growing conditions,
some patience, and a long period of warm weather. The Victoria
growing
in the pool offered a very special backdrop to the Friends of the National
Arboretum Gala in early October.
A
Victoria
seedling in late March. Two important factors for good germination are
high light intensity and consistently warm water temperatures (85°F).
The germination period may vary from 3 days to 3 months. This fragile
young plant will produce leaves up to eight feet in width in a few short
months.
Seedlings growing in a 130 gallon portable tank inside the greenhouse.
Seeds were germinated both in cups of soil or without soil in plastic bags.
Water quality is very important at this stage. Each tank has mechanical
and biological filtration to keep nutrient levels balanced in the water
and to prevent the growth of unwanted bacteria and algae. An ultraviolet
light source helps to control algae. Submersible heaters ensure that
the water stays nice and warm, and an air stone helps to aerate the water.
Live fish were added as an ammonia source for the nitrogen cycle.
The tank is a carefully controlled aquatic ecosystem with a biologically
balanced aquatic environment.
It's
May and it's getting crowded in that tank! The water temperature is reduced
to slow growth and to acclimate the plants to the cooler weather they'll
have to adjust to outdoors.
A small leaf of Victoria cruziana. Even at this stage of
development, this species of Victoria may have rimmed leaves.
It's
June and the water platters are ready to go in the pool. The container
is three feet in diameter and one foot deep. A clay loam soil with little
organic material is used. The stones on top of the soil keep it from
washing out of the pot and also protect the roots from the Japanese koi
that live in the pool.
Plants are placed in the pool as quickly as possible so they aren't
damaged by drying out in transit from the greenhouse. A lot of help
is needed to lift the large, heavy pots after they have been filled with
clay loam and stones. It takes four people to float the container to its
final destination in the pool.
After the plants had been in the pool about one month, warm temperatures
and large amounts of fertilizer spur rapid growth. Each plant has
three or four leaves, and each new leaf is larger than those that grew
before it.
Equipment malfunction led to the loss of almost half the water in the pool over the course of one evening in June. The water was replaced, but the ecology of the pool was disrupted. A thick bloom of algae resulted that continued through most of July. Pictured here is a developing leaf with a small amount of algae-laden water held in the depressions in the leaf. The algae did not slow the growth of the Victoria plants.
In mid July, efforts to establish equilibrium in the pond were underway.
Remaining algae is visible near the top of the photograph. The leaf
on the plant in the foreground was overturned by wind.
The same overturned leaf several days later. Note how the edges of the leaf bend upward in an attempt to reach the sunlight.
By mid August, the ecology of the pool is getting back to normal.
The algae is beginning to disappear and the plants are growing by leaps
and bounds in the hottest part of the summer.
Victoria cruziana is the species with the tallest rims on the
leaves. It is believed that the rims help the plant to position its
leaves so they do not overlap. The result is that all leaf surfaces
have their entire surface in the sun. Victoria amazonica,
visible on the left, has much shorter rims on the leaves. This plant
is also much smaller because it prefers very warm water temperatures, around
90°F, that are hard to attain even in the heat of summer in Washington,
DC. Victoria cruziana is much more tolerant of cooler
water temperatures.
The plants reached their peak in mid September. Each plant has
five or more leaves and flowers are opening almost every day.
Victoria flowers start out as a tight ball at the water's surface.
As the petals expand, the four sepals begin to part.
Open flowers may be as large as a volleyball. In hot weather,
they open white the first day and gradually develop a pink coloration as
the day progresses. The flower closes as the sun sets and opens the
following morning. In its second day, the flower is deep pink or
almost red in color. Individual flowers last only two days before
they begin to deteriorate. The flower pictured here grew in mid October;
the combination of pink and white is a characteristic of flowers grown
in cool temperatures. Late season flowers that must brave cool weather
may also last longer than the standard two days.
The Friends of the National Arboretum staged its gala event honoring the accomplishments of Lady Bird Johnson and her Beautification Committee on the terrace near the pool. Although the event took place in early October, it was a very hot day with high temperatures in the 90's.
As night fell, special lighting brought out the tropical beauty of the
Victoria.
The leaves slowly disintegrate as water temperatures cool in autumn.
By mid November, growth is at a standstill and plants are gradually losing
leaves. Because the plants require a large indoor space heated to
a very high temperature, we do not save plants over the winter. New
plants will be started next spring from seeds.
Curator Mark McGuiness snorkeling in the pool to get a different perspective
on the Victoria.
Want to learn more about Victoria water platters? Click
here.
Back to the Arboretum Home Page
Last Updated January 31, 2003
URL = http://www.usna.usda.gov/victoria.html
