Growing Produce In A Floating System

Floating Lettuce Production

Growing vegetables in floating systems is a viable alternative to soil production. By focusing on crops with short roots, the floating system offers the opportunity to grow continuously throughout the year. Studies conducted by the University of Arizona conclude that by using a simple system, in one production period growers can produce around 1,400 high quality heads of lettuce obtaining high prices in the market.

A Deep Flow Hydroponic System (DFHS) allows the grower to produce leafy vegetables with the roots completely submerged in water. The grower applies the nutrients before submerging the transplants, which are held upright in Styrofoam boards. Because the plant roots are submerged they’re able feed on the nutrients in the water during their growth stages until harvest, which is approximately five weeks after planting for lettuces.

Beginning Production

First off, you’re going to need a container to fill with water. You can choose to use either a flat or deep container depending on the space you’ll need for your plant roots. Myles Lewis, a graduate with a BA and MS from the University of Arizona and founder of Arizona Vegetable Company, recommends using white containers, or buying black ones and painting them white.

In his presentation during a guided tour through his production area during the Annual Greenhouse Production and Design Short Course, Lewis explained the importance of using pelleted seeds and transplants with a polymer binder: “Pelleted seeds are five times more expensive than non pelleted seeds, however, the difference is that with pelleted seeds I achieve up to 99 percent germination each and every time the plant is grown under good conditions. In regards to the substrate that holds the transplant, there are some that contain a polymer binder that maintains form under the water, which prevents the system from clogging.”

Nutrient Application

“Macro and micro nutrients like to work together. If you apply them together in low volumes of water they’ll precipitate out of the solution forming gypsum rock at the bottom of the tank,” explains Lewis.

According to Lewis, you can prevent this by storing and mixing the nutrients separately. For example, you can begin by adding the first nutrient mix when the tank is a quarter of the way full and the rest of the nutrients when the tank is half way full. The same technique applies to liquid nutrient solutions.

“The most important thing is to mix the nutrients well—you want to achieve a good distribution. For example, if you’re mixing liquid acid, acid is heavier than water, and if you don’t mix it well it’s going to sit at the bottom of the tank causing a pH of 1 at the bottom of the tank and a pH of 7 throughout the rest of the tank. That’s not good for the plant.”

Another example is copper application. Given its weight, it’s important to mix it well with the water, which will turn it green temporarily until it fades completely.

“It’s best to add the nutrients while you’re filling the tank instead of filling the tank then adding the nutrients later, since nutrients displace water. Adding them at the end will flood the tank with nutrients,” Lewis states.

After you’ve added the nutrients it’s important to apply the Styrofoam covers immediately because algae can form in as quickly as 24 hours.

Biological Control

“After placing the transplants in the covers, I don’t touch them until they’re ready to harvest. Each time my hands don’t touch the transplants it’s one opportunity less to contaminate the product,” Lewis comments. In addition to providing the plants a sterile environment it’s critical to use sticky yellow and blue traps to attract pests, to keep the greenhouse at a constant temperature of 70°F, and also to use fans to protect the plants.

“By using fans, two things are happening: one is that I’m blowing away insects that can’t fly against the current created by the fan, keeping them away from the production system, and the second is that one of the most common physiological problems is tip-burn, a calcium deficiency, which can be remediated by applying air to the stomata zone.

Lewis explains that when the climate is too humid, the plants can’t breathe and as a result can’t move calcium and water through their systems, which causes death. When you apply air, that air disrupts the humidity of the environment causing plant transpiration. “At that moment you’ll see the plants begin to grow a little faster.”

Satisfying The Local Market

One of the advantages of this simple production system is that it allows the grower to adapt their offering according to market needs. Among the most commonly grown vegetables in this type of system are mustard, red onions, scallions, cabbage, basil, watercress, and some cut flowers.

The system offers growers the opportunity to harvest and sell specialty lettuces with their roots still intact at market, obtaining a higher price than other lettuces. Depending on the crop, you can achieve a harvest in 3 to 5 weeks, however, if you’re growing different crops, you need to keep in mind that those crops will attract different pests according to the preferences of the pests.

Leave a Reply

One comment on “Growing Produce In A Floating System

  1. Growing Produce in a Floating System sounds great but the author failed to tell us about the structure, the pool; that is, size, depth, filtration and circulation of the water. and if were to do this inside one of our greenhouses, how do we go from one crop in containers to one swimming in water?

More From Plant Culture...

May 22, 2015

Nexus Greenhouses Is Optimistic For Expansion Into New Markets

Cheryl Longtin and Mike Porter, who own Nexus Corporation, say they were excited to attend the grand opening of Gotham Greens’ new structure atop the new Whole Foods grocery store in the Gowanus neighborhood in Brooklyn, N.Y., when it opened in December 2013. The project is just one example of some of the new and expanding markets that Nexus Corporation has expanded into over the past few years. Jeff Warschauer, vice president of sales for Nexus, says the company has enjoyed getting to know and working with the founders of Gotham Greens, Viraj Puri and Eric Haley, and Jennifer Nelkin Frymark, the chief agriculture officer, on their innovative approach to business. “They are very excited and work hard internally – just great people,” he says. “From our perspective, it’s great to see that excitement and vision. The employees there are happy and there’s no turnover; they’re only adding new people […]

Read More
Farwest2015

May 20, 2015

2015 Farwest Show Announces Second Annual Equipment Innovation Day

The second annual Equipment Innovation Day will be Tuesday, Aug. 25, prior to the 2015 Farwest show, which will be August 27-29 in Portland, Ore. Equipment Innovation Day, which was enthusiastically received in 2014, offers a real-time opportunity to see new heavy and automated nursery equipment in action. The demonstrations take place in manufacturing and nursery settings, adding value to the showcase. Attendees will be able to talk with participating manufacturers and learn first-hand from innovative growers who use the equipment in daily operations. The day-long event will be held at the main manufacturing plant of GK Machines, Inc., Donald, Ore. Further demonstrations of field equipment will take place at the nearby nursery of A&R Spada Farms, LLC. Bus travel to and from the event is planned, starting at and returning to the Oregon Convention Center. Attendees are welcome to provide their own travel to and from the site. Preregistration is required. The cost […]

Read More
Bee On Flower

May 20, 2015

White House Task Force Releases Pollinator Health Strategy

An interagency Pollinator Health Task Force commissioned by President Obama released its “Strategy to Promote the Health of Honey Bees and Other Pollinators” on May 19. The strategy, released in accordance with the Presidential Memorandum issued last June, is accompanied by a Pollinator Research Action Plan, which outlines needs and priority actions to better understand pollinator losses and improve pollinator health. The recommended actions will be supported by a coordination of existing federal research efforts and accompanied by a request to Congress for additional resources to respond to losses in pollinator populations. Pages 47 through 52 specifically address pesticides and pollinators. The report calls out plant production, native plants, mosquito control and all urban uses in its Pollinator Action Plan. RISE (Responsible Industry for a Sound Environment) says it supports the goals of improving pollinator health and habitat contained in the White House Pollinator Task Force’s release of its National […]

Read More
Latest Stories
Bee on a Sedum

March 17, 2015

4 Key Pollinator Research Projects To Be Funded By Hort…

The Horticultural Research Institute will grant $125,000 in financial support for four key projects as part of the Horticultural Industry Bee & Pollinator Stewardship Initiative. The Initiative has three primary goals. First, to convene a task force to develop a bee and pollinator stewardship program, including creation of best management practices for plant production. Second, to identify and fund research that will help answer key science questions and fill gaps needed to design and refine the stewardship program. Third, to seek to positively position the horticultural community and its customers by collaborating with other compatible groups interested in augmenting pollinator habitat and protection.

Read More

March 11, 2015

Pollinator Initiative Promotes Bee-Friendly Talking Poi…

AmericanHort and the Society of American Florists are working tirelessly with the ornamental industry's Pollinator Stewardship Initiative on a number of new projects.

Read More

February 11, 2015

Infusion Technology Boosts Seed Performance, Study Sugg…

Seven-year-old wheat seed germination can increase by as much as 83 percent, according to a Vital Force Technology Study that looks at the effects of energy infusion technology on plant vitality.

Read More

February 3, 2015

American Floral Endowment Accepting Research Pre-Propos…

If you are pursuing a floriculture research project, now is the time to apply for funding through the American Floral Endowment. Research pre-proposal applications for 2015-2016 funding are due to AFE by June 1, 2015.

Read More

January 27, 2015

Marijuana’s Trajectory And Ascent To Horticultural Cr…

Marijuana growing is poised for change as growers and researchers focus on improving production practices.

Read More

December 9, 2014

Greenhouse Production: Two Years Of Basics & Beyond…

Greenhouse Grower's Basics & Beyond articles cover some of the latest news and research going on in greenhouse production. Here are article links for the last two years.

Read More
GrowIt! App Wins Gold At Design100 2014 US Mobile & App Design Awards

November 24, 2014

GrowIt! App Wins Gold At Design100 2014 US Mobile &…

The social garden app GrowIt! takes the Gold Winner award at the design100 2014 Mobile & App Design Awards.

Read More

November 10, 2014

The Perennial Farm Joins HGTV HOME Plant Collection

The Perennial Farm joins the HGTV HOME Plant Collection growers' network for 2015.

Read More
AmericanHort

November 4, 2014

AmericanHort Publishes Revised American Standard For Nu…

AmericanHort announces the revised American Standard for Nursery Stock (ANSI Z60.1) is now available for industry use. The Standard reflects the consensus of the industry regarding how nursery stock — living plants other than annuals — should be specified and sold within the trade.

Read More

September 26, 2014

Master The Art Of Watering

Watering is elemental to healthy plants, but one of the hardest concepts for new employees to master in the greenhouse. Recommend these tips to start them off right.

Read More

September 16, 2014

Ball FloraPlant’s Las Limas Facility Provides Gro…

Ball FloraPlant’s Las Limas farm in Esteli, Nicaragua, is one year away from full production, but sales and quality from the two-year-old facility are right on track.

Read More
Erysimum 'Cheers' from Darwin Perennials

September 15, 2014

Darwin Perennials Takes Production Offshore In Bogota, …

With its recent purchase of a farm in Colombia, Darwin Perennials is ready to amp up supply of its perennial genetics, to provide growers with tried-and-true varieties and comprehensive production specifications.

Read More

July 23, 2014

Plan Now To Prevent Bract Edge Burn On Poinsettias

Reduce fertilizer and water, and allow your poinsettias to develop slowly during the final four weeks of production to avoid bract edge burn.

Read More

July 11, 2014

Growing Your Crops Above Their Base Temperature

Lowering temperature set points in the greenhouse may help you combat rising heating costs.

Read More

May 1, 2014

Growers Report Nutritional Problems On Geraniums

In recent weeks, several growers have contacted Michigan State University Specialists about leaf discoloration on geraniums, especially the purpling of lower leaves.

Read More

April 22, 2014

How Two Postharvest Care Products Worked On Potted Plan…

What your potted plants look like at retail translates to sales or fails. North Carolina State University researchers report on how two postharvest care products performed.

Read More
Dianthus 'Passion' from Emerald Coast Growers

March 27, 2014

Growing Dianthus Successfully

Here's some advice on transplanting and producing this classic perennial favorite.

Read More
Aquilegia canadensis

March 10, 2014

Tips For Producing Aquilegia

Advice on planting, temperature, vernalization, lighting and more on columbine from Emerald Coast Growers' head grower Josiah Raymer.

Read More