Read about Steve Stroupe

FUN with IFD’s
[Improvised Fertilizing

by Steve Stroupe, Alabama USA
Click images to enlarge

DISCLAIMER: While this article purports to contain bona fide horticultural information, the nature of the subject matter and some of the ensuing experiments seemed to dictate a rather playful and tongue-in-cheek approach, despite the potential utility of the information ...

This article also provides information about aquatic plant culture designed to help water gardeners cope with their aquatic horticultural needs. But cultural information is not the same as cultural advice -- the application of information to an individual's specific circumstances. Although the author of this article has gone to great lengths to make sure his information is accurate and useful, he recommends that all readers consult a professional if they are desirous of professional assurance that this information, and the readers’ interpretation of it, is correct, and appropriate to their particular situation. 

There appears to be a burgeoning, and long overdue interest ... in the US anyway ... around Nutricote as an aquatic plant fertilizer. (See Fertilizing Waterlilies, One Grower’s Perspective in WGI Online 4.3) One of the questions which invariably arises whenever this subject is being discussed is; “What about re-fertilizing?” In this regard alone, tablets are demonstrably superior because the plant nutrients are bound in a solid tablet which lends itself to relatively easy soil insertion through standing water. Nutricote is manufactured in a loose prill* form which is a bit more challenging to get down easily to the root zone of an established aquatic container or landscape planting. Osmocote manufactured a “tablet” or “plug” at one time, constructed from prills held together with a bonding agent, but it never really seemed to catch on. In terrestrial fertilizing applications, it is usually desirable for the fertilizer to be evenly distributed or incorporated into the media. This is true with aquatics as well, but is usually not practical** when re-fertilizing aquatic plants in situ.

* “A prill is a small aggregate of a material, most often a dry sphere, formed from a melted liquid.”
** An exception to this is mentioned later on in the article

While some of the following suggestions may appear cumbersome and time consuming, this perception must be weighed against the time and effort of tablet insertions during the growing season multiplied by the number of plants as well as the considerable expense involved with purchasing tablets. Depending upon the length of one’s growing season, variety of plant being fertilized ... coupled with the “type” (release duration) of Nutricote used, a single fertilizer application can last two years or even longer with little or no supplemental fertilizer.

Here in central Alabama USA, [USDA Zone 7] I get at least two full years out of my [Type 360] Nutricote applications with hardy waterlilies planted in 16” x 7” (40cm x 18cm) containers. No supplemental fertilization is necessary during this period, and the blooming is phenomenal!

< N. 'Laydekeri Fulgens', summer 2009
See large image for cultivation details

Fertilizer costs, as well as labor, are significant factors when contemplating any fertilizer regimen. The Manufacturer’s Suggested Retail Price [MSRP] for a nationally renowned brand of 4000 count, 5 gram (0.18 ounce) aquatic fertilizer tablets is $535.08 [US dollars]. That’s 20,000 grams of fertilizer or about 44 pounds for a cost of $535 at full retail price. Even a moderately skilled Internet sleuth can find a 50 pound (22.7 kilograms) bag of Nutricote delivered via UPS for a cost of less than $100* ... from any number of sources, which makes the tablet fertilizer cost over five times as much. Added to this initial cost is the fact that these tablets are putatively applied to a waterlily at the manufacturer-recommended rate of 2 tablets per gallon (3.8 liters) of soil every two to four weeks during the growing season. This application rate can be compared against a Nutricote application rate of no more than once every two years even in some warm climates [USDA Zone 7 in my particular case].

* There is no MSRP or “retail” price on a 50 pound (22.7 kg) bag of Nutricote, as it is a professional end-user item, rather than a consumer product. While large nurseries will buy truckloads of Nutricote from a blending facility such as Florikan, most smaller nurseries buy from grower supply companies which distribute for these regional blenders, and many of these horticultural supply firms will sell direct to consumers because it doesn’t create a supply channel conflict with their existing greenhouse customers, because greenhouse operators are also end users rather than resellers of these products.

The incentives to innovate and experiment with Nutricote delivery systems are more than compelling on at least two major fronts ... time and money.

When challenged by Kit Knotts a while back to help her devise a Nutricote delivery system which would be practical when re-fertilizing large plants grown in her earthen bottomed concrete ponds, I started thinking about this problem.

In my world, the largest container I normally use for my hardy waterlilies is a 16” wide x 7” (40cm x 18cm) deep no-hole plastic pot. Tropicals are rarely potted in anything larger than a standard 5 gallon (19 liter) nursery pot. When I re-fertilize these hardy waterlily pots, I simply remove them from the pond in late winter or early spring before the floating leaves start to grow, turn them gently upside-down, directly on the ground ... or on a soft hay cushion if one is faint of heart ... remove the pot, add more Nutricote to the bottom of the pot, replace the soil mass, give the container a short drop or two on the ground in order to re-seat the soil mass firmly, and then the plant is placed back in the pond. I like this method because it gets the fertilizer right down to the roots zone, and without any trauma to the plant. Nothing else needs to be done for at least two years unless the waterlily requires dividing in the interim ...

So until Kit’s request, I never needed to address this particular problem.

The logical place for me to start thinking about this challenge was with the Osmocote method of gluing prills together into a homogenous “tablet” or “plug”. I briefly toyed with the idea of taking plastic ice cube trays, spraying them with a non-stick cooking spray such as Pam, filling them with Nutricote, then binding them together them with a dilute solution of water-soluble, white glue such as Elmer's. For some reason this idea never had much appeal with me and seemed too messy and cumbersome ... even if it had worked well, which was by no means certain.

My next idea was to take some Nutricote, roll it up in a paper towel, twist the ends up to prevent spillage, and then seal them with a bit of Elmer’s glue. I christened this application method the “Doobie Delivery System”. This paper towel cylinder or “cigarette” filled with Nutricote can be inserted into a hole in the soil mass made by a round wooden handle or a PVC pipe of the appropriate dimensions ... just like pushing a tablet down with a finger, or by making a pilot hole with a dibble stick first, except on a much larger scale.

While the paper toweling is biodegradable, using the dibble stick or “ramrod” to rupture the paper towel cigarette by punching it a couple of times after it’s been seated in the hole, will only increase the efficacy of this system ... rupturing the toweling will spread the fertilizer around in the hole and surrounding mud. 

I really thought had a winner with this method, so I excitedly called Kit, who for some reason seemed considerably less than enthusiastic about this idea, and muttered something along the lines of “not really having the time to sit around during the winter rolling Nutricote cigarettes”.

My next idea was to take some Jiffy brand peat pots, fill them with Nutricote, apply a thin coat of Elmer’s glue on the top layer of the prills, making sure that I contacted the sides of the peat pot with the glue as well. This insured that the top layers of prills were securely bonded to the peat pot as well as each other, and would not spill out during storage or insertion.

Square peat pots were all I had on hand for my prototypes, but round ones should be used instead -- because of structural integrity, much better selection of sizes, and perhaps most importantly, round pots mitigate the oft-quoted difficulty of trying to stuff a square pot into a round hole.

This is the best delivery system I’ve found thus far for the dibble/cavity application method when large amounts of Nutricote need to be applied through standing water. Peat pots are relatively inexpensive, biodegradable, available in a number of sizes, quickly and cheaply configured, and will hold up well during storage and application. As with the paper towel option, it is best to rupture the peat pot with the ramrod/dibble before sealing the cavity entrance.

The most low-tech solution to this problem is of course to punch the desired number of holes in the soil mass, insert a similarly-sized PVC pipe down to the bottom of each hole, place a funnel at the other end, and simply pour the proper amount of Nutricote into the hole, slowly withdraw the pipe, and then close the hole. Nutricote will sink readily, so if the hole is not positioned at too shallow an angle, this method works reasonably well, although it’s not nearly as fun as some other methods ... and the tablet application methodology is proving a difficult addiction to overcome. The above described method is simply way too easy ...

There are undoubtedly many more options too, but the baseline criteria for a successful Nutricote aquatic delivery system seem to be permeability, biodegradability if possible, and sufficient structural integrity to survive fabrication, storage, brief immersion, and forcible insertion into the pilot hole.  

< A paper coffee filter for a drip coffeemaker filled with Nutricote, gathered, and secured with a twist tie is another viable option. 


Even perforated polyethylene weed fabric should work well, and although it’s not readily biodegradable, it is extremely tough, and enjoys the advantage of being able to contain large amounts of fertilizer without rupturing prematurely. Old or mismatched socks, nylon stockings, old bandanas, etc. ... a lot of things could be conceivably recycled along these lines. >

Large gelcaps are another option, but may not be cost effective for everyone. Those who find that the method of pot removal and flipping is simply too physically demanding with a large container may find the gelcap method to be an acceptable alternative which doesn’t differ significantly from the tried and true tablet delivery method ... except for the fertilization intervals. Veterinary gelcaps are readily available in sufficiently large sizes to hold a sizable amount of Nutricote fertilizer. The largest size I’ve seen is an SU7 [Supersize??] which appears to be around 3” long (8cm) by 3/4” (2cm) in diameter. Here are some sizes currently being manufactured by one company.

Single dose balling gun - US$1.00 

Recently I had occasion to speak with Jamie Beyer of Midwest Waterscapes in Iowa USA. We were discussing Nutricote and I mentioned the gelcap idea to him. Jamie, who has a background in wildlife biology and is also quite knowledgeable about various aspects of animal husbandry, mentioned the existence of a “balling gun” which, despite what some readers may be speculating at this point, is actually a device deployed by farmers and veterinarians to deliver “bolus” (ball) or gelcap medications ... The word “bolus” is Latin for “a round mass” but one definition has come to mean a round preparation of medicine. 

These balling guns are used to place and dispense “balls” of medicine down the throats of otherwise unwilling farm animals who have yet to master the skill of taking their medication voluntarily with a glass of water. Balling guns come in both single shot and repeating versions, and can be had for as little as $1 for the cheapest plastic single-shot versions, and up to $50 for some really slick-looking pump action multidose repeaters. 

Multidose balling gun 

Multidose balling gun 

They come in many shapes and sizes depending upon a number of variables such as the size of the animal, and the size of the gelcap, “bolus”, or “ball” to be dispensed. While I’ve not used any of these devices yet, the guns appear to merit some serious investigation. If nothing else, they look like fun, and you can get one to try for as little as $1.00 US.

It’s also entirely possible that these balling guns can deliver homemade “balls” of Nutricote fertilizer made with more primitive and less expensive materials than gelcaps. 

Depending upon one’s circumstances, a plain, roundpoint shovel can be the most effective Nutricote delivery system. When Greg Wittstock, CEO of Aquascape, Inc., was cleaning out his large backyard pond, he was faced with an even larger problem; his pond was constructed with a 45 mil rubber liner, but was covered in a thick layer of heavy Illinois soil topped with pea gravel. Hundreds of waterlilies had been planted directly in the soil years ago. With the water pumped out of the pond, Wittstock scraped the gravel back at intervals amidst the tangles of partially exposed rhizomes, dug holes in the dirt below the rhizomes, threw in shovelfuls of Nutricote, closed the holes, and threw the gravel back over the dirt. When standing water is eliminated from this equation, simpler solutions readily present themselves. 


I tend toward admittedly silly extremes sometimes when contemplating solutions for various problems, and I’ve had some fleeting, but highly impractical, thoughts around modifying paintball guns to fire high velocity Nutricote-filled gelcaps through standing water directly into mud-filled containers of waterlilies. 

No mention of Nutricote delivery systems could be made without at least one reference from the delightful little book titled Backyard Ballistics by William Gurstelle which contains [among other things] a highly-detailed set of plans for building the famous Potato Cannon, which is manufactured from PVC pipe and uses ignited hairspray as the projectile [potato] propellant. Even a crude version of this potato cannon can hurl a 1 pound (.5 kilogram) Idaho spud for a considerable distance, and at an amazingly high velocity. So I’m thinking that you could hollow out a large baking potato, fill it with Nutricote, and ...
Or ... following this idea a bit further ... the lead shot in a shotgun shell could be replaced with a “slug” of Nutricote prills bonded together by [water-soluble] Elmer’s glue for the first ever, frangible*, or AET [Advanced Energy Transfer] 12 gauge aquatic fertilizer shell ... or perhaps I’ll just replace the lead shot with loose Nutricote and do some experimenting with shooting distances, patterning, soil penetration, and water depths?   

A 12 gauge field load with 1 ounce of lead shot has a muzzle velocity of around 1200 feet per second [fps] and a muzzle energy of 1400 foot pounds, [ft/lbs] although the same volume of Nutricote prills replacing the lead shot would weigh considerably less, resulting in a dramatic reduction of muzzle energy ... we certainly don’t wish to puncture our pondliner with this high-velocity fertilizer application system!! Collateral damage to pond fish is of course another legitimate consideration which will need to be addressed at some point. I may try this "shotgun" approach sometime just for the sheer fun of it ... 

* ”A material is said to be frangible if through deformation it tends to break up into fragments, rather than deforming plastically and retaining its cohesion as a single object.”

If one is ever traveling in rural Alabama near Birmingham sometime in the future, one might hear a lengthy series of rather loud bangs emanating from some secluded waterlily ponds ... Those sounds will likely indicate that I’ve simply gotten too old to flip those 50 pound pots around any longer ...

Fertilizing Waterlilies, One Grower’s Perspective in WGI Online 4.3

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