Pre-Empt: An organic hydroponic fertilizer

Organic hydroponics is possible! We can implement organic practices for hydroponic systems by using nutrient solutions derived from organic plant and animal material or naturally mined compounds. In order to certify the organic origin for a product you must look for OMRI-listed products. The Organic Materials Review Institute (OMRI) is a private, nonprofit organization that determines whether or not a product qualifies as organic under the USDA’s National Organic Program.

Continue reading Pre-Empt: An organic hydroponic fertilizer

The importance of knowing basics of plant nutrition

By Karla Garcia, Hort Americas Technical Services

Plant nutrition is a key factor in growth and yield. But how can we know which nutrient is missing? Or which is the best fertilizer for our crop?

In learning about plant nutrition, we first need to know there are nutrients required in greater quantities than others. The nutrients that are essential for plant growth are called “macronutrients”. The rest of the nutrients also essential for plant growth but in lower quantities are called “micronutrients”.

Continue reading The importance of knowing basics of plant nutrition

Considering mixing your own fertilizer solutions?

It’s not that hard to do once you understand some fertilizer basics.

By Deidre Hughes

Mixing your own fertilizer solutions might seem like a daunting task at first. But once you understand some fertilizer basics you’ll realize it’s not that hard to do. One of the biggest benefits of mixing your own fertilizer solutions is the amount of money you’ll save. Another benefit of mixing your own solutions from dry fertilizers is that it requires less storage space than pre-mixed fertilizers which are often in liquid form.

Continue reading Considering mixing your own fertilizer solutions?

Do you want to sell the freshest, most flavorful and fragrant cut basil?

How you grow and process fresh cut basil will impact the flavor and shelf life of the harvested product.

Basil is one of the most popular culinary herbs. Whether grown as a potted crop or for fresh cut sales, basil is an herb that’s in demand year-round. Growers looking to add edibles to their product mix should consider basil to be a must-have herb in their product offerings.

Continue reading Do you want to sell the freshest, most flavorful and fragrant cut basil?

Fertilizer trials look at leafy greens, herb growth in hydroponic production systems

Early results from fertilizer trials in Hort Americas’ research greenhouse show knowing the levels of nutrients in fertilizer solutions can go a long way in avoiding problems with deficiencies and toxicities.

Hort Americas has retrofitted a 12,000-square-foot greenhouse in Dallas, Texas, for the purpose of studying edible crop production in a variety of hydroponic production systems. The greenhouse is also being used to demonstrate products offered in the company’s online catalog.

Tyler Baras, who is the company’s special projects manager, is overseeing the trialing of leafy greens and herbs in five different production systems.

“We’ve got a deep water culture or raft system using Hort Americas’ fertilizer blend with calcium nitrate and magnesium sulfate,” Baras said. “We are using that same nutrient mix in a nutrient film technique (NFT) system and a capillary mat system.

“I’m using Terra Genesis organic fertilizer in a vertical grow tower. I’m also using the same organic fertilizer for all of the seedling propagation in a flood-and-drain vertical rack.”

Tyler Baras, special projects manager at Hort Americas, is overseeing the trialing of leafy greens and herbs in different production systems, including deep water culture and nutrient film technique. Photos courtesy of Tyler Baras, Hort Americas
Tyler Baras, special projects manager at Hort Americas, is overseeing the trialing of leafy greens and herbs in different production systems, including deep water culture and nutrient film technique.
Photos courtesy of Tyler Baras, Hort Americas

Baras said the fertilizer recipe he is using in the deep water culture and NFT systems is based on general recommendations from Cornell University and the University of Arizona for leafy greens crop production.

Differences in nutrient levels

The deep water culture system has been running for three months. The water reservoir for the system is 8,000 gallons.

“Even if water evaporates, since it is such a large body of water, the electrical conductivity (EC) doesn’t really move much,” Baras said. “The EC has been very stable during the three months it has been operating. The reading has barely moved.”

The first trial with the NFT system, which has a reservoir of about 140 gallons, lasted for three months.

“Every week I added an additional 40 gallons of water on average to the NFT reservoir,” Baras said. “The water is evaporating and the salts are accumulating a lot faster in the NFT reservoir than in the deep water culture system. Because the NFT system has a smaller water reservoir, the quicker evaporation rate and the water replacement in the reservoir, has caused the EC to shift a lot more.”

One of the goals of the fertilizer trials is to see what salts are accumulating in the NFT system and to see how long the system can run before it has to be flushed.
One of the goals of the fertilizer trials is to see what salts are accumulating in the NFT system and to see how long the system can run before it has to be flushed.

Baras said even with the changes in nutrient levels all of the plants have been performing well.

“I haven’t seen any nutrient deficiencies or toxicities even as the fertilizer recipe has shifted over time. We have been trialing a wide range of crops, including butterhead and romaine lettuces, kale, spring mixes and basil. I’m trialing a lot of crops to figure out when these crops start to be impacted by possibly too much salt accumulation. I haven’t seen anything yet that is alarming.

“One of the things that I have seen over the years working with fertilizers is how wide the acceptable range is for plants to grow well. Between the NFT and deep water culture, the NFT is using half the nitrogen and the plants are performing very similarly. There are recommendations for EC, but none of these fertilizer levels are set. I have some systems that have 20 parts per million phosphorus and some that have 50 ppm and the plants look the same. Most general recommendations say 40-50 ppm. I’ll have some solutions that have 3 ppm iron and others that have 6 ppm iron. It is interesting to see how wide the range is for a lot of these nutrients and the crops are performing the same.”

During the three months that the deep water culture system has been running the electrical conductivity (EC) has been very stable with plants showing no signs of nutrient deficiencies or toxicities.
During the three months that the deep water culture system has been running the electrical conductivity (EC) has been very stable with plants showing no signs of nutrient deficiencies or toxicities.

Baras said he has seen a slowing of plant growth in the NFT system.

“I’m not seeing any deficiencies or toxicities, but the crops have slowed down about a week over the deep water culture,” he said. “Depending on the crop, it’s taking a week longer to reach either the plants’ salable weight or height.

“The slowing in growth could be related to the nutrients. This could be useful information for growers. If they are checking the EC, which may have been 2.3 when a crop was started, if there is a slowing of growth, growers may want to have a water test done. The test could show that the amount of nutrients might be changing.”

Identifying what makes up the EC

During the three months that Baras had been running the NFT system he never flushed the system.

“All that I’ve done with the NFT system is add water and additional fertilizer to maintain a targeted EC,” he said. “One of the goals of the trials is to see what ions are accumulating in the system and to see how long I can run the system before it has to be flushed. When I started the target EC was 2.2-2.3. I still achieved the target EC at three months, but the composition of what was actually in the water changed.

“Originally the NFT fertilizer solution contained about 185 parts per million nitrogen. At the end of the trial the EC was the same but there was only 108 ppm nitrogen in the solution. The calcium concentration was originally 250 ppm and ended at 338 ppm. Sulphur was originally at 80 ppm and rose to 250 ppm. Nutrients have accumulated as the water evaporated. Solely going by the EC meter reading doesn’t tell the full story of what is in that water. The EC of the fertilizer solution that I started with is the same as the EC for the fertilizer solution three months later. The difference is the ions that are making up that ending EC.”

Herb production with organic fertilizer

Baras is growing a variety of cut herbs in vertical grow towers. The plants are fertilized with Terra Genesis, a molasses-based organic fertilizer. He said Hort Americas has been hearing from tower growers who are interested in trying to grow organically.

“What we are seeing is the organic fertilizer solution can change a lot over time,” he said. “The fertilizer tank solution matures as time goes on. With the organic fertilizer, the nutrients tend to balance out as the solution is run longer.

“Our city water contains calcium and some magnesium. These elements are actually the nutrients that the organic fertilizer is slightly low in. So as I run the system longer, through the addition of city water, I actually start to see an accumulation of both calcium and magnesium, which actually helps balance out the total fertilizer recipe. The balance of the nutrients has improved over time.

A variety of cut herbs are being grown in vertical grow towers and fertilized with Terra Genesis, a molasses-based organic fertilizer.
A variety of cut herbs are being grown in vertical grow towers and fertilized with Terra Genesis, a molasses-based organic fertilizer.

The pH was fairly unstable as it seemed to be going through several biological waves. It was moving rapidly between high and low. As I run the tank solution longer the total alkalinity has increased, which has stabilized it. The biological activity has also started to stabilize. The pH has stabilized in the upper 5 range. For the plants grown organically I have seen deficiencies pop up. The deficiencies were reduced as the fertilizer tank solution ran longer. The deficiencies appear to have balanced out.”

Baras said one noticeable difference between the NFT, deep water and vertical grow towers is how much slower the plants grow in the towers.

“I don’t know what to contribute the slower growth to yet,” he said. “It could be trying to determine the best fertilizer rate for the fertilizer. It could be the crop selection, because most of the crops in the towers are different from what I’m growing in the NFT and deep water culture.

“I’m going to start a deep water culture and NFT trial using organic fertilizer. I’ll have three different organic production systems running simultaneously so I will be able to compare the plant growth in each system. I’ll also be able to compare the growth of the same crops grown with organic or conventional fertilizers.”

Controlling biofilm, disease pathogens

Baras said one of the issues that can arise with using organic fertilizer is the development of biofilm in the irrigation lines that can cause emitters to clog.

“I am incorporating a product called TerraBella, which contains beneficial microbes,” he said. “These microbes help mobilize certain nutrients, like phosphorus, which can promote the formation of biofilms. This biofilm buildup is usually more of a problem with high water temperatures.

“About every six weeks I add a booster application of the beneficial microbes depending on the production system. The deep water culture system has a larger reservoir so I am not replacing evaporated water as often. For the other productions systems, like the NFT and grow towers, where I am replacing the water, I am incorporating the beneficials more often. For these systems, the fresh city water that is added dilutes the fertilizer solution. Also, there is chlorine in the city water that possibly could negatively impact some of the beneficial microbes.

For more: Hort Americas, (469) 532-2383;

David Kuack is a freelance technical writer in Fort Worth, Texas;


Products being used in greenhouse trials



Pre-Empt Organic Hydroponic Nutrients


Proudly brought to the commercial hydroponic and organic grower by Hort Americas and specifically developed for recirculating nutrient film technique (NFT), the Pre-Empt Hydroponic Nutrient is packed with the essential micro- and macro-nutrients, amino acids and vitamins plants hunger for!

Pre-Empt goes through a five stage fermentation process which is above and beyond other products by incorporating molasses with other natural plant extracts. This process packs Pre-Empt with essential macro-nutrients, micro-nutrients, amino acids like humic and fulvic acid, as well as an array of vitamins which build a full spectrum of nutrients that plants desire.

  • Excellent for lettuces, basil, leafy greens and culinary herbs

  • OMRI-listed

  • We suggest pairing with Terra Bella to naturally promote the uptake of nitrogen and other essential nutrients for plant health. The combination of aerobic and anaerobic microbes works throughout the root zone to increase crop yield and resistance to disease and pests.

  • For further resources including a quick video and Organic Fertilizer Programs, click here!

Pre-Empt can be used in conjunction with a solution grade organic gypsum (calcium sulfate) and magnesium sulfate.


Hort Americas is an innovative leader in North America’s controlled environment agriculture industry (CEA) and strives to continually innovate in agriculture via premium technical support, professional salesmanship, unmatched customer service and outstanding products to our customers in the United States, Canada, Mexico, and the Caribbean.

For questions and support, click here!

Webinar on “Managing Nutrient Solutions for Hydroponic Leafy Greens and Herbs”

If you missed the e-GRO webinar “Managing Nutrient Solutions for Hydroponic Leafy Greens and Herbs” on Jan. 22, 2016, which was sponsored by Hort Americas, you can still view the webinar on YouTube.

Hydroponic greens and herbs are produced in systems with recirculating nutrient solutions. In order to maintain productive and quality crops, it is important to know how to properly maintain the nutrient solutions. Dr. Chris Currey at Iowa State University and Dr. Neil Mattson at Cornell University discuss strategies for managing pH and EC, formulating nutrient solutions and identifying common nutrient disorders.

Part 1: Common production systems, pH and EC management

Presented by Dr. Chris Currey, Iowa State University


Part 2: Nutrient solution recipes, common nutrient disorders

Present by Dr. Neil Mattson, Cornell University

Monitoring Irrigation Water Quality

Testing your irrigation water quality is important and
should be done regularly.  Frequency of water
samples is dependent on several factors. Growers should test their irrigation
water at least twice a year if producing crops year round.  I know one grower that tests their water
weekly!  At Hort Americas we are becoming
inundated with fertilizer requests and nutritional recommendations.  The first question we’ll ask is “Do you have
results from a recent irrigation water quality test?” If the answer is yes,
great, please forward a copy of the results to us.  If the answer is no, please have your irrigation
water quality tested.  Next question,
“How do you sample your irrigation water?” Collecting water samples correctly
is important to ensure the results are accurate. 

If you are not testing your irrigation water, why
not!?!  That is one of the first things
you should do before a single seed is sown. Why? Well, if you don’t measure it,
you can’t manage it.  On one hand, you
could be undervaluing your irrigation water by adding unnecessary soluble nutrients.
On the other hand, your irrigation water may be unsuitable for crop production
and/or require additional treatment before use. What do I mean?  The irrigation water chemistry made need to
be treated to remove or correct nutritional issues. Or, your irrigation water
may have unwanted sediments that must first be filtered.  Entire books are written on irrigation, so we
cannot cover everything in one edition of an e-newsletter.  For now, let’s first focus on collecting the irrigation
water sample.  As you recall, last month
I shared some videos on growing winter salad greens created by Dr. Brian Krug
from the University of New Hampshire.  Once
again, Dr. Krug has composed both a valuable how-to article and a video to help
you correctly collect an irrigation water sample. 
Check out this article from October, 2012 or, watch another
FloriCAST video by Dr. Brian Krug.
Irrigation Water
Sampling Summary:
Have the right tools e.g. hose or spigot,
bucket, collection bottle, paper towels, submission form, envelope etc.
Flush the water line/hose for at least 3 to 5
Fill collection bucket
Use a clean collection bottle/container (at
least 8 ounces)
Submerge and fill the collection bottle and cap
under water (no head space)
Complete a submission form (if provided by
testing lab)
Dry and label the collection bottle accordingly
Deliver the envelope to the testing lab
Wait for results
Send Hort Americas a copy of your results J
For more information on irrigation water quality you may
want to read the following extension publications.  Many state extension agencies have produced
similar articles. These are simply two examples of such articles.  Check with your local extension specialist as
they may have more information relevant to your geographic location.

You may also want to
visit the Water Education Alliance for Horticulture. The Water Education Alliance for Horticulture is a team
of researchers and industry experts led by the University of Florida.  Their mission is to “help growers conserve
irrigation water and manage water quality issues.”

Written by Dr. Johann Buck, Technical Service Manger at Hort Americas 
Posted by Maria Luitjohan  

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Organic Fertilizers with Dr. Danielle Treadwell at the University of Florida

Florida producers adding structures and organic
By David Kuack
An increasing number of Florida fruit and vegetable producers
are looking at implementing some type of protected environment production.
University of Florida-IFAS associate professor Danielle Treadwell said producers
are looking at a variety of structures including greenhouses, high tunnels and
hoop houses. She said some producers are looking at taking a portion of their
field acreage and adding covered production.
The reason for adding the structures varies. Treadwell
said producers are looking to take advantage of new or expanding markets for
specialty crops. Other producers plan to extend the season for crops that can
be damaged by freezing temperatures. Some producers are looking for
opportunities to expand their product mix with organically-grown crops.
Treadwell said market demand is the most important driver
for the construction of greenhouses, but that water is also a key factor.
“When you start talking about high tunnels and hoop
houses, producers are looking for water savings through better freeze
protection,” Treadwell said. “When there is a freeze in Florida the protection
is coming from overhead irrigation. A single farm can use millions of gallons
of water per freeze event. Producers of high value crops like blueberries and
strawberries are exploring high tunnel production to moderate the temperatures
under these structures and to apply less water.
“Florida producers are seeing increased restrictions on
water use,” she said. “They want to be ready. There are 18 million people in
the state so there is a high demand for water.”
Increased interest
in organic production
Some of the producers who have used traditional methods
and inputs are looking at taking advantage of the increased demand for organic
products. Treadwell said some of these producers have customers asking for
these products while others are looking to diversify their product mix. She
said this has led to producers asking suppliers for organic fertilizers
specifically for their crops.
“There are more manufacturers that are developing organic
fertilizers,” Treadwell said. “Some companies that have historically served
conventional farmers are now expanding their offerings because their customers
are diversifying.”
Treadwell said those producers who have adopted biologically-based
management strategies such as biological pest controls should have an easier
time converting to an organic production system.
“Producers who grow fruits and vegetables organically are
using biological controls,” she said. “There are very few controls approved for
use with conventional pesticides and even less for growing organically. When
you have an organic system in the greenhouse you have to rely on biological
controls. If you have an established biological program in the greenhouse you
are good to go. Through the efforts of university
and the producers we have done it and we have done it well here in Florida for
a number of years.”
organic fertilizers
Treadwell said producers seeking to implement organic
production and who already have a biological pest management system in place
should only have the fertilizer program to work out.
“How to keep the biology in the pot optimized so that
nutrients are transformed at a pace that the plants need–that’s the
challenge,” Treadwell said. “It’s finding that sweet spot of which fertilizer
to use, what analysis, and really honing down that application strategy.”
She said there are number of manufacturers that will
custom mix dry granular as well as soluble fertilizers that are compliant with
the USDA’s National Organic Standards.
“Producers can develop a relationship with a supplier
that does custom mixes and start experimenting to determine the best blend for
their crops. Then the next step is to put together a system of mixing tanks,
injectors and emitters that will deliver the fertilizer without clogging.”
Treadwell said it is best to mix the exact amount of
fertilizer solution that is needed. Holding the fertilizer solution at high
temperatures in the greenhouse can increase the rate of biological activity and
negatively impact the quality of the products.
A number of techniques have been tried at the university
to try to keep the fertilizer solution cool for a longer period of time. These
have included placing pop-up canopies over the tanks and injectors in the
greenhouses, wrapping the fertilizer tanks in reflective Mylar mulch and
submerging the fertilizer tanks in kiddy pools that contain recirculated well
“Because the fertilizers used in organic systems are
plant- and animal-based nutrients with some minerals added in, these liquids
are suspended particulates in solution,” Treadwell said. “It’s not like
ammonium nitrate, which is a salt with ions that truly dissolve in water.”
Finding injectors that can handle the particulates in organic
solutions can be an issue.
“The injectors do clog,” Treadwell said. “It’s also very
easy for algae to grow so it’s really important to flush the injectors well
after applying the fertilizer solution.”
She said high greenhouse temperatures can also take a
toll on fertilizer injectors.
Organic fertilizer
Treadwell said because most organic fertilizers are complexes
of multiple ingredients, the availability of individual ingredients may occur
at different rates. For this reason, she said, producers need to pay attention
to electrical conductivity levels during the season to have a better
understanding of release rates.
Even with the potential for excessively high or low soluble
salts, Treadwell said a limiting factor for certified organic fertilizers can
be the amount of nitrogen they contain.
“In compliant organic fertilizers the highest nitrogen
analysis available for dry granular fertilizers is around 15 percent,” she
said. “For solutions, the highest nitrogen analysis is around 5 percent. If
it’s greater than 15 or 5 percent, producers need to be sure that the
fertilizer is USDA compliant before they use it. That means a producer has to
apply quite a large volume of fertilizer in order to sustain the rapid growth
of the plants in a greenhouse because the temperatures are hot and the plants
are growing fast. It can be a little tricky, but it can be done. It just
requires a lot of management.”
Treadwell said using a combination of organic granular
and liquid fertilizers is helpful.
“It’s helpful to have a steady supply of nutrients in the
growing media using the granular forms and then supplementing with the liquid
form periodically through the season depending on the plants’ needs,” she said.

For more:
Danielle Treadwell, University of Florida, Department of Horticultural Sciences, (352) 273-4775;
David Kuack is a freelance
technical writer in Fort Worth, Texas,
Organic Fertilizers use in strawberries (Spanish).

The University of Florida has produced a series of online
educational videos called Virtual Field
( The videos present information on a variety
of topics (hydroponic production systems, soilless media, nutrient solution
delivery, pest management, harvesting and marketing) with visual support
including instructional how-tos. One of videos was made by associate professor
Danielle Treadwell who discusses the use
of organic fertilizers
in greenhouse vegetable production.Visit our corporate website at

Kimitec Launches its North American Website

Its finally up and live! is the perfect place to go to learn about the latest trials on this organic and non-organic line of fertilizers.  From Amifort to Tundamix, the Kimitec Group (along with the support of American Clay Works in North America) continue to focus increased yield, plant health and vigor.  Please follow this link to learn more about Kimitec Trials in hydroponics, commercial greenhouses and general agriculture.

Visit Hort Americas for additional technical information and to buy your Kimitec today.

Visit our corporate website at