THE CULTIVATION OF VICTORIA
An Occasional Series of Horticultural Notes
from the Royal Botanic Garden Edinburgh, No 3
by Pat Clifford, Senior Horticulturist,
Click images to enlarge - More images linked in the text
Victoria amazonica Sowerby has been cultivated in Britain
since the 1840s. In this paper the cultivation of this species
at the Royal Botanic Garden Edinburgh is outlined with reference
to its native environment, including propagation, planting out,
general maintenance, flowering and pollination.
Victoria amazonica Sowerby is in the water lily family
Nymphaeaceae. It is endemic to the Amazon basin in South America,
primarily in Guyana, Brazil and Bolivia. The largest of all water
lilies, the Victoria water lily is found in the warm,
still waters of the swamps and ox bow lakes of the Amazon River.
This paper describes its history and cultivation in Britain and
at the Royal Botanic Garden Edinburgh (RBGE) in particular.
Victoria amazonica was first discovered in 1801 by the
Bohemian botanist Tadeas Haenke in Bolivia (Anderson, 1965).
However, it was not until 1837 that the English botanist John
Lindley established the genus Victoria and described the
species Victoria regia in honour of Queen Victoria (Lindley,
Soon after Lindley's description, attempts began to cultivate
the plant in England. However, it was not until 1849 that it
was successfully brought into flower in a specially designed
glasshouse at Chatsworth, the estate of the Duke of Devonshire.
It is said that Joseph Paxton who was the Duke's head gardener
at the time, based the design of the glasshouse in which it was
grown on the complex, but regular and structurally sound, system
of veins on the underside of the leaf of the water lily. The
design of this glasshouse was inspirational and was subsequently
used as the basis for the designs for the Crystal Palace, built
for the Great Exhibition of 1851.
In its natural habitat the Victoria water lily is a
perennial plant that can survive for many years because of the
uniform day length of approximately 12 hours in the tropics.
Indeed, a plant may be kept for many years in the temperate regions
with the aid of supplementary lighting. However, in higher latitudes
the plants lose their condition when light levels drop in winter
and it is therefore best treated as an annual and propagated
from seed each year.
In late January 5cm clay pots are filled with riddled loam.
The pea sized seed
is placed on top of the loam and half covered with chick grit;
a quartz grit approximately 2mm in diameter. At RBGE we have
found that viability seems to drop quite drastically as the seed
ages so it is always best to use the freshest seed available.
The pots are then placed to a depth of 100mm in water heated
to 32°C. At RBGE a 1000
litre tank situated in the tropical propagation area is used
for the propagation of a number of tropical aquatic plants including
this water lily. Germination usually occurs within 2-4 weeks
are potted on in to 10cm pots when the second set of true leaves
have developed. Plants are potted on as necessary until planting
out in the final container in the display pond.
By the end of March the leaves on the young plants should
be 300mm across signalling the correct time to plant them in
their final tubs. At RBGE the Victoria water lilies are
grown in the 'People and Plants' house (formerly the Tropical
Aquatic House) in the main range of public display houses. The
pond in which they are grown holds 82,000 litre of water and
has a surface area of 80ml which allows three plants to grow
to full size. The water is kept at a constant 29°C and the
air temperature in the glasshouse has a minimum day temperature
of 24°C and a night minimum of 19°C. However, in summer
temperatures of up to 30°C during the day are common.
Just before it is time to carry out the planting operation
is drained, last year's soil is emptied from the tubs and
replaced by new, fresh loam. The loam is roughly chopped but
not riddled. Care must be taken when sourcing the turf for the
loam stack and the stack should have had at least 18 months to
break down before use. There were disastrous results to the water
lilies one year at RBGE when turf was donated from a bowling
green. This was due to the residues of herbicides that had been
sprayed on to the bowling green over the years.
The tubs in which mature plants are grown are 600mm deep and
900mm in diameter and, when in place, the top of the tubs sit
400mm below the surface of the water. Once the tubs are filled
with loam a 30mm deep layer of coarse grit or gravel is placed
on top to ensure that the loam does not float out of the tub
when the pond is refilled.
The plants are moved from the propagation area to the display
house in May and placed on the newly filled tubs. The pond is
refilled and they are left for a week to acclimatise and to allow
the petioles to lengthen. The purpose of this is that when they
are planted in the tubs the leaves will sit flat on the surface
of the water. When transplanting to the final growing place great
care is required not to damage the fleshy root system. It is
also essential that the plant is pushed firmly into the loam
and that the gravel is swept back over the planting hole. This
minimises the risk of damage by small nest burrowing fish such
as Cichlids (Cichlidae) of which there are many in the pond.
Unlike most ponds that are used to display Victoria
water lilies, at RBGE we also manage to grow many other genera.
These include many Nymphaea hybrids, Nelumbo nucifera
(Nelumbonaceae), Pistia stratiotes (Araceae), and Eichhornia
crassipes (Pontaderiaceae). The theme of the glasshouse is
to display plants which humans use and so rice, Oryza sativa
(Graminae), sugar cane, Saccharum oficinarum (Graminae),
and Cyperus papyrus (Cyperaceae) are also grown.
A determined Nymphaea pushes through a
Victoria pad to bloom.
One of the main requirements of the Victoria water
lilies is a feeding regime that provides them with plenty of
nitrogen and to this end high nitrogen fertiliser
balls are made at RBGE. A wheelbarrow of poor soil is taken;
any soil will do providing that it is not too clayey or contains
large stones, An inorganic fertiliser with an NPK ratio of 2:1:1
is added to the soil at a ratio of 1:3. Water is added until
the mixture is sufficiently sticky to fashion in to balls approximately
the size of an apple. The balls are left to dry and harden in
a cool dry place.
Throughout the growing season the plants are fed every 7 10
days, the technique
being to insert three balls to a depth of 300mm at the point
where the roots terminate. Later in the season when the plant
roots have filled the tubs the balls are pushed in wherever possible.
At this depth the ball will break down effectively and the feed
will percolate through the root system.
With such heavy feeding and intensifying light levels the
plants put on a massive amount of growth in early summer. By
mid June the plants are fully grown and the largest leaves can
reach up to 2m across. At this time the plants are at their most
spectacular and the maintenance schedule 'moves up a gear'.
Great care must be taken when working around the plants because
of their spiny nature. The spines on the underside of the leaf
can cause a very nasty wound. This is always more dangerous when
working in standing water because of the possibility of Leptospirosis
(Weills Disease) which is carried in rat urine. Twice per week
a member of staff goes into the pond to remove the older leaves
in order to make space for the new leaves. From a personal viewpoint
I prefer to allow some of the surface of the water to show because
it contrasts beautifully with the leaves and provides some great
reflections of the glasshouse structure to visitors. In order
to achieve this some of the smaller leaves have to be removed
as well as the large ones. The alternative to this method of
displaying the plants is not to remove the leaves and to allow
the water surface to be completely covered with many leaves competing
with their neighbours for maximum sunlight. This approach enables
the visitor to see what a huge and impressive plant the Victoria
water lily really is.
Although the Victoria water lilies are not susceptible
to many pests or diseases there is a problem with one particular
species of aphid
early in the growing season. At RBGE the policy is to try and
use biological control whenever possible and this is particularly
important when dealing with ponds, which may or may not contain
fish. The predatory midge Aphidoletes
aphidomyza (Cecidomyiidae) is very effective indeed.
A batch of 1000 pupae is released when the plants are planted
out. This is repeated weekly for the next four weeks. The adult
midges hatch almost immediately and fly off, laying eggs near
the aphid colonies. The eggs hatch and the emerging larvae begin
to feed on the aphids. They do this by biting the leg of the
larvae and injecting a paralysing toxin. The larva then begins
to suck the fluids from the aphid. Each larva can consume up
to 100 aphids. The life cycle from egg to adult takes approximately
28 days depending on the temperature of the environment.
FLOWERING AND POLLINATION
The plants begin to produce large flower buds as early as
June. At RBGE the buds produced in the first month are cut off
to encourage the plant to put all its energy in to leaf production.
The Victoria water lily is night flowering, which is a
pity because the general public never see or smell the first
Pollination is a complex procedure and in the wild the flowers
rely on beetles to do the job for them. On the first night the
bud opens producing a spectacular white flower. It is the size
of a melon and gives off a heady scent which attracts the beetle.
The temperature inside the flower is higher than that outside
and the beetle crawls, into the tent like structure of petals.
Inside this tent there is plenty of nectar and while the beetle
is happily feasting the petals close around the insect and trap
While the beetle is inside the flower begins to change. First
it cools down and changes colour, initially to pink and then
to purple. When the beetle first entered the flower it was receptive
to pollen from another plant, but once it has changed colour
it is no longer receptive and cannot be pollinated. Instead its
anthers ripen and release pollen of their own, coating the beetle
in the fine powdery substance.
The following evening the flower opens and the pollen covered
beetle flies off in search of another white flower where it will
be rewarded with warmth and food. In order to enter the new flower
the beetle will have to squeeze past the stigma thus pollinating
the new flower (Bridgewater and Milliken, 2002).
At RBGE dedicated staff return to the gardens in the late
evening perform the function of the beetle. The pollen laden
anthers of a second night flower are gently snipped off and laid
in a tray. They are taken over to the first night flower on another
plant. The petals are carefully prised open until there is a
big enough hole in the centre of the flower into which the anthers
and pollen are deposited. A soft brush is used to move the pollen
about inside the flower, thus dusting the stigma and pollinating
After pollination the seed pod begins to swell and within
about six weeks it ruptures. To ensure that all the seeds are
harvested a muslin bag is tied over the pod once it looks ripe.
Up to 500 seeds can be produced per pod. These are covered in
a glutinous white aril which needs to be washed off before the
seeds are stored. They are kept in distilled water or wet sand
at 14°C until it is time to sow them the following year.
The plants themselves give an excellent display from May until
mid October when, due to the rapidly decreasing light levels
the plants begin to deteriorate. The leaves begin to grow much
smaller and softer, and eventually they rot off. When this happens
the plant is removed and the pond returns to its more sedate
winter state. Due to late planting in 2004 the Victoria
water lilies in the RBGE pond lasted longer in to the winter
not removed until the first week of December which was very
VICTORIA CRUZIANA AND VICTORIA 'LONGWOOD HYBRID'
V. cruziana, another species of water lily is displayed
in the same pond as V. amazonica. This species is found
primarily in Argentina, Paraguay and Uruguay. It has a more southerly
distribution than V. amazonica and therefore does not
require such high temperatures for seed germination or cultivation.
At RBGE it is cultivated in the same way as V. amazonica
and positively thrives on this treatment. Although the leaves
do not grow to the same dimensions as V. amazonica they
have a far more pronounced upturned lip which can measure 150mm.
The Longwood Hybrid water lily is also grown at RBGE when seed
is available. This hybrid was developed in 1960 at Longwood Gardens
in Pennsylvania, USA. The pollen was taken from a flower of V.
amazonica and used to fertilise the flower of V. cruziana.
The resulting seeds produced a spectacular plant that is now
grown around the world.
The progeny of this cross could not have turned out better.
It displays the best characteristics of both parents; these are
the extraordinary size and deep red colour to the undersides
of the leaf of V. amazonica, and the large lip and relative
hardiness of V. cruziana. These characteristics combined
with its hybrid vigour have bred a truly beautiful plant. In
the near future it is hoped that all three of these plants will
be grown in the same pond and that interpretation will be provided
to bring the world of hybridisation to the general public. There
is surely no better plant than the Victoria water lilies
to tell this particular story.
ANDERSON, E. (1965). Missouri Botanical Garden
Bulletin Vol. LIII No. 5
BRIDGEWATER, S. and MILLIKEN, W. (2002). Unpublished
Audio Tour Texts for RBGE
KNOTTS, K. Victoria's History www.victoria
[Accessed March 2005]
LINDLEY, J. (1837) A notice of Victoria regia,
a new nymphaceous plant discovered by
Royal Botanic Garden Edinburgh
Mr. R H Schomburgk in British Guayana. Shakspeare Press. London.