In an effort to avoid bankruptcy heating
waterlilies over the winter, Charles Leach reports on his -
View of snow outside
from the sun room
Experiment to Save Energy with
Mini-Heaters - Part 2
(Click here to review
by Charles Leach, Ohio USA - Zone 6
Click images to enlarge
Buggy Summer & Strange Fall: The past summer and
fall were hard on our tropical waterlilies. For starters, given
a summer and fall with almost no rain, we spent most of our time
watering terrestrial plants rather than giving the waterlilies
proper care. While we weren't paying sufficient attention, weevil
infestations twice forced us to totally cut back most of our
tropicals in the in-ground pools and tubs.
For some strange reason the plants in our above-ground tubs,
that we pass by constantly, had practically no weevil damage
while the plants in the more out of the way in-ground pools were
decimated. In addition to the weevil problem, whitetail deer
discovered that the leaves of waterlilies were a real treat in
a world in which all other vegetation was desiccated. In addition
to eating all the leaves, as they also did with the hardy lilies,
they often pulled the less securely anchored tropicals out of
the pots. Especially late in the season, when they should be
storing energy to get them through winter inside, I would find
leafless crowns of tropicals floating or even laying on the ground
first thing in the morning. Our one 'Green Smoke' was victimized
so often that it was barely alive when brought in for the winter.
In the decades we have been growing waterlilies deer have never
bothered them until the last two years.
In order to give them time to form tubers, we usually bring
our tropicals in just before the first freeze, while they are
still actively growing, but this year days got shorter, temperatures
fluctuated radically over an extended period and many confused
tropicals seemed to be headed toward dormancy, some crowns turning
an unsightly black or starting to mold, with no prospect of frost
to trigger action on our part. Finally, at the beginning of November
I decided to end summer vacation for our tropicals and bring
them in. By then it was too late for some and they died once
inside without forming tubers. Particularly hard hit seemed to
be several night bloomers, 'Red Flare', Nymphaea rubra,
a pink we are evaluating, and 'Trudy Slocum'. Several day bloomers,
including 'Green Smoke' and 'Director George T. Moore' were in
very poor condition for weeks after being brought inside. In
all our years of raising tropical waterlilies, last year was
the worst as far as transitioning them from outside to inside.
Slow Starters: A little more bad news was that one
addition to our collection, 'Frank Trelease', purchased to winter
over in order to give it a head start, was dying back and had
to be moved to what I call triage in a heated and well lit aquarium.
Having new plants barely hang on for some time isn't all that
unusual for us. We have had some take several seasons to establish
themselves. What we purchased as an N. "stellata"
tuber took three years to bloom and turned out to be a red night
bloomer instead of the blue day bloomer we expected. Hardy lilies
'Denver' and 'Hermine' didn't bloom or grow enough to divide
until the third year when I threatened to compost them. Given
the threat they took off, bloomed like crazy and have been exceptionally
prolific ever since. My advice is, if all else fails, try intimidation.
A reviving 'Frank Trelease'
in one of our
Triage: What I call triage came about as a result of
a failed attempt to sprout Victoria cruziana seeds. We set up
two 20 gallon aquariums and carefully followed Victoria Adventure
directions but the precious seeds refused to sprout. To add insult
to injury Euryale ferox seeds, which supposedly sprout and grow
like weeds for other people, in the same aquarium sprouted and
quickly died. I was about to conclude that the set up was cursed
when a few tropical waterlilies that were dying back revived
in the aquariums. Since then these aquariums have become an integral
part of our wintering over facilities. Not very energy efficient
perhaps but quite effective in reviving tropicals starved for
light and or heat. The key to success in perking up declining
tropicals in Triage seems to be catching them before they completely
We also use the triage aquariums to give newly acquired tropical
lily tubers a head start to wintering over. At the left are baby
'Foxfires'. When planted there were two tiny detached sprouts
and three tubers. Two weeks later the plants are well established
and two of the three tubers have sprouted. I highly recommend
starting tropicals in this manner, with water temperature held
at approximately 86° F (29 C) during the winter. Handled
properly you will have established plants when summer comes rather
than bare root starts that may not do much until late in the
season if then.
Late Entries: In mid-November I was about to add several
generic red night bloomers, from the so-called "stellata"
tubers, to the compost heap when it occurred to me that they
might be used in the test instead. The thought of composting
them was painful because they were magnificent plants; practically
identical in every way to 'Mary Francis', which is my favorite
red night bloomer, and far more vigorous through the strange
fall than the 'Red Flares' next to them in the same pool.
Similarity to 'Mary Francis' was the problem. I was afraid that,
if kept, they might somehow get confused with 'Mary Francis'
and possibly contaminate the gene pool. For now they have been
given a reprieve and are wintering in our basement, three small
ones in six inch pots with mini-heaters and three larger ones
in five quart pots; one with one heater, one with two and a control
with none.Even though they were left out through a couple of
below freezing nights and the foliage was dying back, the crowns
seemed to be viable and within a couple of weeks the ones with
heaters in the pots were sprouting.
The image at the right, taken Christmas Day, shows the generic
red in a basement tub. The lush leaves at the top of the photograph
are from plants with mini-heaters in pots a little over a quart
or liter in volume. The less lush leaves at the bottom are from
a plant in a five quart size pot. Evidently the plants are a
little happier in the smaller pots where the mini-heaters raise
the soil temperature a bit more. An early indication of the effectiveness
of the mini-heaters was that the control in the pot without a
heater eventually rotted away.
The Lighting Factor: As you may recall, we are testing
mini-heaters in two areas, a sun room with filtered natural light
and in basement tubs with artificial light. In both areas lighting
may be as significant a factor as temperature. I already know
that some varieties, such as 'Green Smoke' and 'Midnight' need
more light to thrive than has been available in our sun room.
Some varieties such as 'Red Flare' and N. rubra barely
survived the filtered light in the sun room last year without
going dormant and the mini-heater in the 'Red Flare' test pot
didn't help this year. The 'Red Flare' control without a heater
went dormant within two weeks after being repotted and brought
inside, and the one with the heater in the pot was dormant by
the fourth week.
The problem seemed to be that the summer and fall that went by
with hardly a cloud in the sky had given way to a winter so overcast
that there was very little sun at all. Therefore there was insufficient
natural light for most tropical lilies in central sun room pools
and end tubs. When the two 'Mary Francis' and 'Texas Shell Pinks'
in the sun room pool, that had thrived last winter, started to
die back we knew that supplemental light had to be provided.
Our solution, given the need to move quickly, was 65 or 120 watt
grow light bulbs in fixtures that could be clamped to ceramic
blocks left over from a reconstruction project. Not very attractive,
but they seemed to perk up the plants that were not too far gone.
A potential problem with the test plants in the basement tubs
is that some tropical lily varieties, such as 'Red Flare', don't
seem to thrive under our T-8 fluorescent lights while others,
such as 'Hickory Bend Ruth', flourish. We had to cut leaves off
of Ruth on Thanksgiving Day because it was already mugging the
'Leopardess' in the same tub. A comment about 'Antares' in the
Encyclopedia of Water Garden Plants ("Stands up well to
artificial light") indicated that others have noticed that
some varieties like it better than others. I wish we had ideal
and uniform lighting conditions for all the plants in this test
but that isn't the case and we will have to attempt to assess
effect of lighting on test results.
Test Procedure: Harking back to my decades in product
evaluation and development, each variable (individual pot) is
being inspected weekly with plant condition, soil temperatures,
and water temperatures recorded in a composition book along with
any deviation from original parameters. Readers will not be tortured
with full details but they are important when the time comes
to reach conclusions.
Commercial for Heat Mats & Accurate Thermostats:
Our first effort to be more energy efficient in wintering over
tropical lilies and some other tropical plants with floating
leaves was use of heat mats plugged into accurate thermostats.
We went that route initially because of bad experiences with
electric heaters that warm the air around tubs in the greenhouse.
Mechanical thermostats on the units we tried were nearly useless.
Heaters often failed to come on when required and once on they
usually failed to shut off, even when air temperatures exceeded
100° F (38 C) on sunny days.
To overcome the problem I bought heaters with digital thermostats
that could be set to nearly exact temperatures, but rather than
solving the problem it turned out to be a disaster given the
constant power interruptions in our area. Even a momentary flicker
in power, too short to kick our generator on, would cancel out
the thermostat settings and our precious plants would be without
heat. In addition to that problem, heating an entire greenhouse
instead of heating only the water in the tubs was not energy
As noted in Part 1 of this series, we experimented last winter
with using heat mats, underlaid with insulation, under some of
the tubs on the floor and all the smaller tubs on the shelf in
our attached greenhouse. These mats, plugged into an accurate
thermostat, have worked like a charm and should more than pay
for themselves in a couple of years given current energy costs.
Happy 'Mrs. Edwards Whitaker' and other babies
growing in a four
gallon container on the shelf
With only 40 watts / linear foot for the 21" (53 cm) wide
mats under the 40 gallon (151 liters) tubs on the floor and only
20 watts / linear foot for the 12" (30 cm) wide mats on
the shelf, they are not going to warm water much more than 10°
F above air temperature but that saves a lot in overall heating
cost. Looks like they will have to be trimmed back to keep them
in the container very soon.
in a 40 gallon floor tub
on a heat mat
Room temperatures in the greenhouse where these happy plants
are growing have been as low as 62° F (16 C). Even if you
don't choose to go with the heat mats, I would highly recommend
plugging heaters with mechanical thermostats into an accurate
thermostat and that those with digital thermostats be avoided.
Commercial for viviparous tropical waterlilies:
Our viviparous tropical lilies were not included in mini-heater
test because, based on previous experience, keeping the greenhouse
they are wintered in above 65° F (18 C) with an occasional
dip to as low as 62° F (16.7 C) is all that is required to
winter them over. My favorites for winter blooms are 'Mrs. Martin
E. Randig', 'Patricia', 'Paul Stetson' and 'Queen of Siam' that
have bloomed well all winter in the past. 'Lindsey Woods', a
new addition, has bloomed well so far this year although the
flowers are small. Between Christmas and New Year's I took photographs
of a few of the viviparous lilies in bloom in our attached greenhouse.
'Queen of Siam'
1 in WGI ONLINE Journal
How the mini-heaters are working so far: So far so good
but we have not reached the coldest part of winter, when room
temperatures may drop significantly, and it must be noted that
mini-heaters do not bring back the nearly dead or compensate
for insufficient light. Plants have to be viable for the heaters
to help get them through the winter inside. Some varieties in
the sun room are obviously unhappy, a couple actually going dormant,
but this can be attributed to insufficient light rather than
insufficient heat or to the fact that some varieties, especially
night bloomers, tend to go dormant no matter what. In the last
week of November I had a conversation with a very knowledgeable
man with a well-known nursery in Florida about the availability
of a night blooming variety that I wanted to add to my test.
"All the night bloomers have gone dormant by now,"
he said. When I told him that we have kept some varieties, such
as 'Mary Francis' and 'Texas Shell Pink' growing and blooming
all winter, he was amazed.
At this point I think it is safe to conclude that the mini-heaters
that work are keeping the plants warm enough so far. Two of the
Junior aquarium heaters from Wal-Mart and one of the Hydor mini-heaters
were replaced early on in the test however because they didn't
provide much heat. A couple of the Junior heaters that were getting
extra hot, registering readings as high as 112° F (44.4 C)
were moved away from the plants. Otherwise the concept seems
to be working fairly well as evidenced by the image below right
that shows the difference between a 'Mrs. Edwards Whitaker' with
a mini-heater and the control without a heater.
Shortly after this photograph was taken the control was moved
into triage to recuperate but did not survive. 'Hickory Bend
Ruth', 'Pamela', 'Wood's White Knight' and 'Texas Shell Pink'
with mini-heaters are also obviously more vigorous than controls
without heaters while "H.B. Pink Wisp", 'Emily Grant
Hutchings' and N. rubra controls without heaters all died
back while their counterparts with mini-heaters survived if not