Get Yourself into Hot Water!
by Rich Sacher, New Orleans, Louisiana
Read more about Rich Sacher
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For quick success with waterlily seeds, tubers and
Many waterlily and Victoria growers have discovered
that a warm 90° F (32° C) hot tub treatment stimulates
tropical waterlily seeds and tubers into growth. Here's how I
The Hot Tub
I use a black plastic tub, two feet (0.6 meter) square and one
foot (0.3 meter) deep, for my greenhouse hot tub. I put two 1500-watt
aquarium heaters in this tub, and keep it filled with water.
One heater suffices; the second one is insurance in case the
first one fails. I set the heaters at 90-92 F. (32-33 C.) degrees,
and keep a clear Plexiglas sheet over the tub to retain heat,
especially at night. Glass or Saran Wrap works, too. Any of them
retards evaporation and helps prevent heat loss. I add a goldfish
or two to control mosquitoes, and some underwater grasses to
keep the water clear.
Any waterproof container deep enough for the aquarium heater
works. I once used a tall, deep vase to germinate Victoria seeds,
since that was all I was working with at the time. It held two
quarts (two liters) of water, and was deep enough to completely
submerge the heater. I placed the seeds in a Ziploc bag of water,
barely submerged in the vase. This made it easy to remove the
bag and check their progress.
Seeds of Tropical Lilies
Tropical waterlily seeds respond to 90° F (32° C) temperature
for promoting fast germination. Please understand that I am talking
about TROPICAL waterlily seeds, NOT seeds from hardy lilies!
I have no experience germinating hardy lily seeds, but I read
that sometimes they germinate while being stored in water in
a refrigerator. Hardy waterlily seeds must be kept wet. By contrast,
many tropical waterlily seeds can be dried and sprouted later.
Hardy waterlily seeds seem to require a period of COLD, wet storage
before they germinate. I would not recommend putting them in
90° F (32° C) water until research shows what effects
that may yield.
To sprout seeds of tropical waterlilies, place seeds in Ziploc
bags of water, along with their name tag. Float the bag of seeds
in the hot tub. Examine the seeds weekly. Remove and plant those
that germinate sufficiently, and return the remaining dormant
seeds to their hot tub for subsequent germination. Not all seeds
germinate at once, so practice patience during the germination
period that can stretch to six weeks or more.
The seeds of most Australian waterlilies respond to germination
in bags of warm water. Their bigger size allows for easier handling
than the smaller seedlings of most other tropicals.
If you prefer to plant seeds in soil, cover them with a layer
of fine sand. Place the seedling tray into the hot tub to promote
faster germination. If you have fish or snails present, employ
some method of keeping them away from the seed pan. Otherwise,
the fish or snails may eat or dislodge the seedlings as they
grow. Use screening or a raised, clear plastic covering over
the seed pan to protect against fish and snails. I sometimes
use two clear plastic saucers...one for the soil, the other for
a top...and paper clip them together at the rims. Once the seedlings
emerge, relocate the seed pan to a sunny pond where with 75-80°
F (24-27° C) water where they should progress quite nicely.
Their relocation makes more room in your hot tub for more seeds
Many tropical waterlily tubers remain viable but dormant for
many months...sometimes for several years. Use the hot water
treatment to break their dormancy, thereby forcing the tuber
into growth. This is particularly useful for getting an early
start on the growing season. Many tubers do not begin growth
until the pond water consistently maintains a temperature around
85 F. (30 C.). By then, half the growing season may be lost.
However, by starting the tubers into growth in March or early
April, you gain a significant head start on the growing season.
You can force many Australian waterlily tubers into growth with
three or four weeks of hot tub treatment; without this early
intervention, these tubers may not sprout until July or August...too
late to produce sizeable plants for the current season. Sprout
tubers in Ziploc bags of water, or just dump them loose into
the hot tub if you are confident you can correctly identify the
plants that emerge.
^ Note this photo of Nymphaea immutabilis, forced to sprout
in early April, following three weeks of 90° F (32° C)
hot tub treatment. The plantlet is ready for removal from its
tuber. Pot the plantlet. After a few more weeks in the hot tub,
the tuber should produce another plantlet.
This spring, I took 20 Victoria 'Longwood' seeds, removed
the seed coat at the operculum with a razor blade, and placed
the seeds in a sealed plastic sandwich bag of pond water. Then
I placed the bag in the hot tub with various dormant waterlily
tubers. Within five days, the water in the bag turned tan, because
some of the pigments from the cut seed coat leached into the
water. Whenever this happens, I change the water in the bag,
so it stays clear and makes observation easier. In 15 days, a
third of the seeds had sprouted their filiform leaves.
I like to remove the seeds from the bag at this stage, and plant
them. However, other growers wait for the first or even second
hastate leaf to form before planting the seeds. The seed contains
enough stored food to support these first leaves. However, once
some tiny roots appear, I plant the seeds in soil. (See details
on the Victoria-Adventure site.) I return non-germinated seeds
to their bag of water, and put them back into the hot tub.
Once Victoria seeds germinate, you DO NOT have to keep
the young seedlings at hot tub temperature! Plant them in 75-80°
F (24-27° C) water with full sunlight, and they grow very
nicely. The hot tub temperature simply speeds up the seeds' germination.
From the initial 20 seeds I started with, 15 germinated within
three weeks, and 11 of those took root and now thrive in six-inch
(ten-millimeter) pots. This method typically produces a better
than a 50% success rate...not bad for Victoria, which
can be difficult to start. I attribute my success to the hot
Finally, I think too many Victoria addicts obsess over
the quality of their water, adding chemicals to control algae,
or making frequent water changes. A Victoria seedling
does not need light to germinate, only warmth; after it shows
hastate leaves, then it needs light.
Once a Victoria seedling floats its leaves, it does not
care if there are algae in the water! Basking on the water surface,
the leaves enjoy all the sunlight they want. Algae indicate an
excess of nutrients in the water. This is a GOOD thing, as far
as the Victoria seedling is concerned. The Victoria
tank photo shows abundant algae growth on the water surface.
Note how happy the Victoria seedlings are...now; please
leave them alone until they need repotting!
In summary, it takes heat, not light, to break dormancy of Victoria
seeds, tropical waterlily seeds, and tropical tubers. They require
light once they produce some leaves, so the hot tub can be small
if you remove the sprouted material every week. Keep seeds and
tubers that have not started growth (including tubers from which
you have removed plants) in the hot tub for further development.
So...if you want success in a hurry...don't be afraid to get
into some hot water!