The article below expresses the
opinions of the author and must not be considered a product
endorsement by WGI. The author has no vested interest in the
Methods may not apply to all growing conditions, soil types,
or all varieties of waterlilies.
Fulgens' spring 2008
See large image for cultivation details
One Grower's Perspective
by Steve Stroupe, Alabama USA
Click images to enlarge
This is a simple article written about a relatively simple
activity ... fertilizing and potting waterlilies. None of what
Im about to disclose here is revolutionary or novel, yet
this information doesnt seem to be widely known or utilized
by the average homeowner or pond installation contractor in more
than a few cases.
The performance of the average waterlily in the average water
garden is usually quite unimpressive. There are two primary reasons
for this: ignorance or indifference. Ignorance because the homeowner
or contractor just doesnt know how to provide optimal growing
conditions for this plant, or indifference because the knowledge
is available but is viewed as too much trouble to implement ...
especially when its time to fertilize or divide. Additionally,
this underperformance may not ever be perceived as a problem
since mediocre performance is the norm more often than not.
The water garden industry itself has been complicit in the
neglect of this problem ... sometimes inadvertently and sometimes
willfully. The industry has been much too complacent about fertilizer
innovation, preferring instead to over-rely on outdated fertilizer
tablet methodology as the only way to accomplish aquatic plant
fertilization. With the exception of a single transient example,
the water garden industry has also expressed little or no interest
in slow or sustained-release fertilizers, preferring the short
term view instead which believes that this technology would reduce
consumer fertilizer sales.
Tablet fertilizers for aquatic plants have been the industry
standard for fertilizing waterlilies long before the first specialty
aquatic tablet was manufactured in 1991. Tablets are certainly
one way to assure that the plant gets a steady supply of nutrients,
but are quite expensive and extremely labor intensive to apply.
This was not such a problem in the 1980s and well into of
the 1990s when water gardening in the US was transitioning from
a mail order specialty into a mainstream product line at local
nurseries. Waterlilies at that time were new, mysterious, and
expensive, so most people would follow the instructions for proper
fertilizing with tablets quite religiously. A typical application
rate was two 5 gram tablets per gallon of soil every two weeks
or month. After the novelty wore off and ponds started getting
larger and sported more plants, less and less people seemed inclined
to adhere to an optimal fertilizer regimen. When gravel ponds
invaded previously held bare liner territory, plant fertilization
became even more problematic for the average homeowner.
Since tablets are so much trouble, then whats the answer?
A fertilizer which could coax maximum performance out of waterlilies,
but needed to be applied only once every 1 to 2 years?
Its already here...
Nutricote is a Japanese-manufactured, patented, polymer
(oleofin resin) coated sustained-release prill*
fertilizer which was developed and/or utilized for rice paddy
fertilization in Japan, so it can easily be called a professional
aquatic plant fertilizer. There are a plethora of peer-reviewed
papers available on Nutricotes outstanding performance
in rice paddy fertilization. Nutricotes primary release
mechanism operates on soil temperature, not relying on
ambient moisture levels like standard Osmocote and its
imitators, which make them largely unsuitable for aquatic use.
Additionally, Nutricote has a much flatter release curve than
standard Osmocote even in terrestrial applications.
Nutricote works just as well under water as it does in terrestrial
applications, which is why it is such an excellent aquatic
plant fertilizer, and is THE commercial fertilizer of choice
for most commercial growers in the US who grow aquatic plants
sub-aquatically. This amazing technology also allows the fertilizer
to follow the natural physiology of the plant, in effect going
dormant with the plant in cooler weather and waking
up with it in the spring.
Nutrient supply through Nutricote
nicely matches the physiology of plant response to temperature.
The release rate of Nutricote is not significantly influenced
by soil moisture levels. (Florikan website)
While soil moisture plays a vital part in the initial activation
of the prill, (dissolves the fertilizer inside the prill),
pH and soil composition can affect release performance in a very
minor way, the gorilla in the room here is soil temperature
... The truly exciting thing about Nutricote as far water gardening
goes is that now homeowners as well as growers can produce incredible
plants without that cumbersome, invasive, horribly expensive,
and problematic tablet-jabbing nightmare.
Since Nutricote release curves are based upon a uniform 77°
F (25 C) [greenhouse] soil temperature, a 360 day formula
can easily last two seasons or more ... even in the deep south
of the USA. Temperatures less that 77° F (25 C) will cause
Nutricote to slow its release rate, while temperatures over 77°
F (25 C) will speed it up. Nutricote application rates are also
based on USDA Hardiness Zones or Nutricote Regions
which are numbered 1 (coldest) thru 4 (warmer) and then Greenhouse
(warmest) in order to help growers to use the correct formulation.
Nutricote Control Release Fertilizer (CRF) is available in release
formulas ranging from 70-540 Day release durations or Types,
with or without micro-nutrients, and in a variety of NPK formulations.
Nutricote is exported from Japan in bulk to selected blenders
throughout the US who then offer various standard and custom
blends to their local grower markets. Florikan in Sarasota, FL,
for instance. For more information on Nutricote:
Technical Information (.pdf)
So are tablets completely obsolete? Not at all. Since Nutricotes
formulas require a kick-in period to start releasing
their nutrients which is roughly equal to 10% of the total
days of release duration, (Type 360 takes 30 days to kick
in ... Type 100 takes 10 days, etc..) tablets are a good
way to supply some readily available nutrients immediately, especially
if an established plant is being shifted up into a larger container.
Upon occasion, and for whatever reason, a nutrient boost may
be required in between fertilizations, and tablets work well
for that application too. Lastly, tablet fertilization is deeply
ingrained in the US waterlily hobby psyche, and even an incredible
product like Nutricote will have some difficulty unseating this
habituated tablet fetish until a baseline level of increased
awareness is reached by consumers and contractors. Some growers
already transitioned to Nutricote some time ago, and it will
only be a matter of time before hobbyists come on board too and
will start to enjoy waterlilies like theyve never before
experienced ... and with virtually no effort with fertilizing.
Nutricote can be purchased by growers direct in 50 pound (23
kilo) bags from US blenders such as Florikan ESA in Sarasota,
FL or from local horticultural supply distributors throughout
the US, although the distributors usually carry just a few formulations,
so it may be worth the extra effort to contact a regional blender
for the precise formulation needed.
Serious hobbyists with sizable waterlily collections would
be better off going this route too, since the cost of an average
formulation in a 50 pound (23 kilo) bag FOB origin (freight
not included) ranges from US$75-$95 and will last indefinitely
if kept reasonably cool and dry. A 5 gallon (19 liter) bucket
and some silica gel desiccant works extremely well for storage.
Hobbyists can buy Nutricote retail in 1 pound (.5 kilo) and
2 pound (.9 kilo) containers under the trade name Red Dynamite
Plant Food (For Flowers & Vegetables). This is actually
Nutricote Type 270, 13x13x13 with Micronutrients.
How To Grow Incredible Waterlilies with Nutricote --
by the numbers
1) FULL sun ... the more sun the better.
2) Rich, heavy dirt in either planting pockets, bags, or pots
... NOT gravel!!!
3) Room to grow. 16x7 (41cm x 18cm) is a considered
a minimum size for a standard waterlily pocket, bag, or pot.
4) Variety or cultivar
Cultivation details with large image
Full sun is self-explanatory. To bloom profusely, waterlilies
need a minimum of 6 hours of direct sun per day. Most can get
by on less, but will not bloom profusely. Some varieties do better
than others on less light.
Good soil is a must. A heavy soil with well-composted organic
matter is ideal, but any heavy garden soil will do. Its
seldom necessary to use commercially bagged soil. Its horrendously
expensive and is usually no better than local screened topsoil.
Gravel: while some marginal plants can squeak by being
directly planted in an unfertilized gravel substrate, waterlilies
should never be subjected to this indignity unless poor to mediocre
plant performance is the objective.
Never plant a waterlily in less volume than a 16x7
(41cm x 18cm) pocket, bag, or pot. 24x7 (61cm
x 18cm) is even better for large landscape plantings, and requires
less frequent maintenance intervals than smaller containers.
Full-size lotus require a baseline minimum of a 24
(61cm) diameter container or pocket but they really do superbly
with 36 (91cm) for an impressive planting. Soil depth on
lotus should be no more than 3 to 4 (8cm to 10cm)
regardless of container size. One thing to remember about container
size ... they will need to be lifted out of the pond at some
point, so keep the size commensurate with your ability to remove
Varieties of waterlilies can make a substantial difference
in overall performance. The Laydekeri family of hardy hybrids
are always top performers when it comes to a multiplicity of
blooms as are some others. Use a knowledgeable grower who can
assist you in selecting the best waterlilies for your area. Avoid
any hardy cultivar with an odorata or tuberosa
root system if planting in a gravel-bottomed pond or a small
container. They are too aggressive and like to run too far too
fast. Tropicals will literally overrun the pond when fertilized
with Nutricote ... really ...
Fertilizer ... Nutricote
Use the 13x13x13 + minors in a Type 360 day formulation
if possible. Ive been lazy for the last several years,
and have just been using a 13x3 with micros in both a 70 and
360 day formulation, as are some of my fellow growers. No doubt
this could be dramatically improved upon ... Under the application
rates found here, use the High Top
Dress rate for your USDA Agricultural zone. (Gram to
volume conversions given below.) One application of Type
360 will last two years at least, in Zones 4-8. I also use this
same formulation (13x3) in a Type 70 day release curve and add
it to the Type 360 when potting in late summer in Zone
7 because the 70 day formula comes on quicker (7 days) and supplies
just enough nutrients for the plants to flush out prior to the
end of the growing season ... lasting until spring when the 360
kicks in again and rocks for an entire two seasons or more depending
Ive always been a fan of the Rich Sacher method of fertilizing
which advocates a heavy hand with fertilizer.
Since Nutricote is so stable in its release, its a good
one to experiment with in regards to megadoses. When shifting
up a 1 gallon (4 liter) hardy waterlily (spring, Zone 7) to a
4 or 5 gallon (15 or 19 liter) waterlily container, I use approximately
2/3 cup of 13x13x13 with minors Type 360 Nutricote, and 5 to
10 each 5 gram aquatic fertilizer tablets. If I were shifting
up in the fall, Id simply skip the tabs. Assuming a US$100
for 50 pound (23 kilo) delivered cost for Nutricote, the cost
of fertilizing a 5 gallon (19 liter) waterlily at this application
rate for 1 to 2 years with Nutricote would be only 70 cents.
This is based on a delivered cost of .0044 per gram buying in
50 pound bags. Consumers buying smaller amounts will pay US$4.97
for a 1 pound (.5 kilo) container of Red Dynamite at Home Depot,
which is slightly more than one cent per gram. At 454 grams per
pound, 2/3 cup of Nutricote weighs 160 grams, which costs only
US$1.70 per application, and will easily last at least one year
and likely two or possibly more depending upon zone, etc., etc.
1 Teaspoon = 5 Grams
1 Tablespoon = 15 Grams
1 Cup = 240 Grams
The technique for potting with Nutricote is fairly standard
as one would expect with just a couple of extras thrown in. If
using a plastic pot, wet the bottom first and then throw the
fertilizer in and swirl until its evenly distributed. The
water helps the prills to be less slippery and more inclined
to stay put.
The same N. 'Laydekeri Fulgens'
plant as above in a different
location, summer 2009
See large image for cultivation details
If shifting up from a small container add an appropriate number
of fertilizer tablets which will give the new potting a really
good start. If starting from a bare-root division, skip the tablets
if you wish and add some Type 70 or just wait for the Type 360
to kick in about a month.
If using a planting bag, add an inch (2.5cm) or so of soil
prior to adding the Nutricote and keep the Nutricote about an
inch (2.5cm) away from the edges of the bag. This will help keep
the fertilizer from leaching too readily into the pond. Since
Nutricote has an extremely stable release curve, it is probably
the safest fertilizer to use in an aquatic environ with fish,
but it pays to be careful nonetheless.
Since Nutricote will last two full seasons even in the southern
USA, the question arises about what to do during the third and
possibly fourth years provided the waterlily doesnt require
repotting at that juncture. I just remove the pot from the pond
well before I expect to see the first emergent leaves in the
spring, place a 6 (15cm) mat of straw on the ground, flip
the pot upside down on the straw, coax the soil mass out, rinse
the pot, apply some more Nutricote, reseat the soil mass firmly
with a couple of shallow drops, and place the container back
into the pond. This can also be done just as effectively in the
fall, and is quite practical for a homeowner with a traditional
pond that uses potted waterlilies.
An alternative, but less effective, method is to take a paper
towel and roll a few Nutricote joints and twist the
ends shut, and use just like fertilizer tablets after first pushing
pilot holes with a stick in the soil, and then using the stick
to ram the fertilizer to the bottom of the hole. Veterinary gelcaps
filled with Nutricote are another alternative to paper towels,
if one really cant seem break the tablet addiction.
This is the cheapest, least labor intensive, and most effective
way Ive found to maintain truly beautiful waterlilies.
While a lot more work should be done with formulations for various
plants, experimenting with various release durations in different
climates etc., this product certainly has a lot to offer for
both the professional and hobbyist grower.
* A prill is a small
aggregate of a material, most often a dry sphere, formed from
a melted liquid. The material to be prilled must be a solid at
room temperature and a low viscosity liquid when melted. Prills
are formed by allowing drops of the melted prill substance to
congeal or freeze in mid-air after being dripped from the top
of a tall prilling tower. Fertilizers (ammonium nitrate, urea,
NPK fertilizer) and some detergent powders are commonly manufactured
as prills. Wikipedia