Getting serious about hydroponic vegetable production

Originally published in Issue 4

The GrowHaus is refining its production methods and product mix to satisfy its expanding customer base.

In July when Tyler Baras took over as manager of The GrowHaus’ hydroponic greenhouse operation in Denver, Colo., he knew that some changes were going to have to be made. Prior to taking the position, Baras had worked at 3 Boys Farm Inc. in Ruskin, Fla., which was the rst certi ed organic recirculating hydroponic farm in the United States. While in Florida, Baras grew gourmet greens and heirloom tomatoes for high-end clientele including Disney World, Epcot and Emeril’s Orlando.

“Before I arrived at The GrowHaus there was a more laid back approach to production practices related to pest management, sanitation and fertilization,” Baras said. “When I was growing organically in Florida there were a lot of little things that had to be done, especially pest control. Even though The GrowHaus is not a certified organic operation, I have taken a drill sergeant approach to production practices. Sanitation, including cleaning of floors and recently harvested hydroponic channels, is now done weekly. And packaging has been upgraded to meet commercial standards.”

When Tyler Baras became at The GrowHaus, he implemented changes that increased lettuce production from 35 cases to over 70 cases per week.
Photos courtesy of The GrowHaus

Circle Fresh Farms distributes about 60 percent of The GrowHaus’ crop, mainly red and green bibb lettuce. The lettuce is marketed to Whole Foods Market and King Soopers. The GrowHaus also has local customers including Denver Urban Gardens, Linger, Marczyk Fine Foods and LoHi Steak Bar. The produce is also distributed in a local food basket program for residents of the Elyria-Swansea and Globeville neighborhoods.

Expanding product mix

Prior to Baras’ arrival at The GrowHaus, the 5,000-square-foot greenhouse facility was producing about 35 cases of lettuce per week. Having implemented the changes Baras initiated has resulted in the production of over 70 cases per week.

“Growing hydroponically takes a lot of attention,” he said. “You constantly have to be looking over lettuce. A disease can pop up quickly. If you don’t handle it right away it can quickly get out of control resulting in unsalable product.”

Baras said some of the plants that had been grown previously at The GrowHaus were used as repellants to insects.

The GrowHaus’ bibb lettuce is marketed to Whole Foods Market and King Soopers, as well as other local customers.

“Crops like dill and cilantro were being grown more for their pest repellant properties,” he said. “Unfortunately, the plants weren’t being grown correctly so they weren’t commercially salable. We eliminated those plants and added more crops that could be sold commercially.”

Baras has expanded The GrowHaus’ product offerings to include a variety of crops including bok choy, top soi, a couple different kale, ‘Rainbow’ Swiss chard, a variety of lettuces, sorrel, nasturtium and pansies. He is experimenting with micro-greens and is trialing additional crops.

One of the environmental differences between Florida and Colorado that has made it easier for Baras to try different crops, especially lettuce, is the relative humidity.

“In Florida it’s very difficult to really cool the greenhouses because of the high humidity,” he said. “Evaporative cooling in Florida is pretty much ineffective. That makes it very difficult to grow lettuce in the summer. In Colorado because of the low humidity, using evaporative cooling I am able to drop the temperature by 20oF.”

Pest and disease management

Baras said his move from Florida to Colorado required a change in the way he produced greenhouse vegetable crops.

“In Florida there were no issues with powdery mildew on lettuce,” he said. “Tomatoes were the crop more likely to have problems with powdery mildew. In Colorado powdery mildew is the major disease that we are dealing with so we have to be really diligent. Sixty percent of what we produce is bibb lettuce. It is susceptible to powdery mildew so it needs constant attention. We use organic controls so applications have to be made when the disease symptoms show up.

As The GrowHaus has added new customers, Baras has been able to expand the product mix to include crops such as kale and Swiss chard that are more resistant to or not susceptible to powdery mildew.

“Diversifying our customer base that will buy a larger assortment of crops will definitely help in reducing our pest and disease issues,” he said. “We have one customer, 25 Farms, that makes up food boxes and wants a variety of items, not just bibb lettuce.”

One problem that Baras left in Florida is insect control issues.

“Insects were a much bigger problem in Florida, primarily white flies and aphids,” he said. “We do encounter aphids here, but they are a much smaller concern.”

Adjusting to a different production system

When Baras was growing in Florida he was using an American Hydroponics and Crop King nutrient lm technique (NFT) hydroponic system. The production system he is using at The GrowHaus is a New Growing System (NGS) that was developed in Spain. Baras said the NGS system is not commonly used in the United States and is installed primarily in high tunnels and not greenhouses. He said the NGS system was designed to allow farmers to grow various crops. Tomatoes, cucumbers, strawberries and lettuce can all be grown in the same base system using different size plastic lm channels.

An advantage to the NGS hydroponic system is the channels can be 30-40 feet long.

Unlike an NFT system in which the water is constantly running, the water in the NGS system is pulsed into the channels. Plants in a NGS system are watered every 10 to 30 minutes for between 20 seconds to 1 minute.

“An advantage to the NGS system is the channel can be longer in length,” Baras said. “With an NFT system there can be issues with low oxygen levels if the channels exceed 10 feet. With the NGS system the channels can be 30 to 40 feet long because they run on a pulse allowing plants to dry out and breath between waterings. The NGS system uses channels with multiple layers of plastic similar to a bag inside a bag. The NGS system also uses fewer water emitters than a NFT system.”

Baras said a disadvantage of the NGS system is that it is difficult to sanitize.

“With a NFT solid plastic channel it can usually be removed relatively easily and dropped into a bleach solution,” he said. “The NGS channels are locked into the system and they are difficult to clean thoroughly with their multiple plastic layers.”

Another potential disadvantage with the NGS system is the potential for the plastic channels to tear or to be cut.

“Since the NGS channel is like a sheet of plastic it can be cut or torn if workers are using scissors to harvest herbs or microgreens,” Baras said. “This can result in having to replace a whole channel, which are rated to last about five years. A NFT system channel can easily last 15 years or more. The initial cost to install a NGS system is substantially cheaper than a NFT system. But the long term maintenance for NGS can be more expensive since the channels have to be replaced sooner, especially if they are damaged.”

 

For more: The GrowHaus, (720) 515-4751; http://www.thegrowhaus.com.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Leave a Reply

Your email address will not be published. Required fields are marked *