January/February – 2000
Story Title: Young’s Greenhouses, Texas
Author: Steven Carruthers
Lettuce, Watercress & Tilapia in Texas
Corporate consolidation and high labour costs are not making it easy for small, family farms. STEVEN CARRUTHERS visits one family that saw change coming, and switched to hydroponic and aquaponic technologies to ensure their long-term survival.
Cooper and Joyce Young, and son Joe, who operate a peach orchard near Wichita Falls, Texas, recognised a changing market environment as early as 1980 when they built their first greenhouse. Today, the Young family operate 10 greenhouses occupying 33,000 square feet (10,000sqm), and grow lettuce and watercress for the ‘white tablecloth’ market. They also raise Tilapia in an integrated aquaponic system.
Labour problems have also meant slowly replacing the peach orchard with pecan trees, which can be mechanically harvested, thus reducing the farm’s dependence on hand labourers.
“My son will probably be the last to work in the peach orchard,” laments Cooper, a 4th generation peach farmer. “A lot of our workers have been with us for years, and my father before me, but their sons are now working in Dallas and Houston in construction and finance and other industries, where the pay and benefits are a lot higher.”
“If you notice, there is a town about every 30 miles, or in the old days about a day’s horse ride,” continues Cooper. “Today, these towns are dying, because there’s no jobs to hold the kids. The transition from peach orchard to greenhouse production has been a gradual process, the move starting at a time when little was known about hydroponic technologies, and greenhouse automation didn’t exist. Cooper planted his first crop (of tomatoes) in soil, and got good results, but the second crop was wiped out by pythium. It was at this point that Joyce attended her first meeting of the Texas Greenhouse Growers Association (now Southern Greenhouse Growers Association) where she heard someone talk on hydroponic lettuce production.
“We learned everything about hydroponic lettuce from the Association,” credits Cooper.
Today, Joyce is a Board member of the Association, as well as the grower at Young’s Greenhouses. While Cooper is responsible for the maintenance, buildings, fertilisers and marketing, Joyce is responsible for the crop’s management.
“We’d been married a long time when we got the greenhouses,” explains Cooper, “and after 2 years we began to step on each other’s toes. That’s when we divided responsibilities. It was necessary, otherwise we wouldn’t have made a living out here, and we’d probably be “divorced.”
Young’s Greenhouses is situated 130 miles (210km) from Dallas, where the cold winds from the north meet the hot winds from the Gulf of Mexico. Temperatures range from minus 4o below freezing in winter, through to 110-118°F in summer.
“In this area most people only grow in fall and spring,” explains Cooper. “The summers are too hot, and in winter it’s too cold.”
Describing himself as a ‘shade tree mechanic’, Cooper designed and built all 10 greenhouses to stand up to the strong northerly winds, as well as the heavy ice they bring in winter.
“The ice just builds up on everything,” he explains. “The power-line poles will go down, and trees will break. That’s one reason why I have stayed with this greenhouse design, and I’m real reluctant to go to bays. These are harder to heat and harder to cool, but they are strong.”
Orientated north-south, each greenhouse is covered with a double inflatable plastic skin to help insulation, and the inside growing environment optimised using thermostatically controlled fans and propane-fuelled air heaters. Cooper improvised automatic shutters by incorporating internal roll-up ends in the greenhouse design – when the fan kicks in, the ends drop.
“All our cold weather comes from the north,” explains Cooper, “so any wind that gets through the front pins the plastic to the back, and stops it there.
“But that’s one nice thing about lettuce – it’s a cool weather plant, and more forgiving,” observes Cooper.
“In summer, cooling becomes critical during the long, hot days,” he warns. “Just a few minutes without my fans and I’m dead.”
A large generator serves as a back-up power source in the event of power failure.
According to Cooper, controlling light levels and the hours of light are just as important as temperature for growing lettuce and watercress.
“Red lettuce needs more light intensity to strengthen its colours, and the reverse is true for green lettuce – the more shade, the greener the crop.
“Watercress is really not a cool season plant,” continues Cooper, “but it is an undergrowth plant that can be found along streams, under the shade of trees. So we need even more shade.”
Cooper shades his greenhouses with layers of lime. Starting early Spring, a high-pressure sprayer is seconded from the orchard to apply a thin layer of lime to the greenhouse coverings. As the days get longer and hotter, the lime coating is thickened. And when the days get shorter and cooler, the lime is allowed to wear away through wind and rain, until the following Spring when the shading process starts again. The plastic coverings are replaced every 4 years.
At the height of summer, dark weedmat is used over the seedling greenhouse to better control the hours of darkness.
“It’s tough when you get those long hot days,” comments Cooper.
Cooper points to heating the air as an inefficient way to heat a greenhouse in winter. Warm air rises and is lost to the plants below. Using high-pressure fibreglass pipes manufactured locally for the oilfield industry, Cooper plans to construct distribution lines to supply warm water heating to the root zone, where it is needed most.
Five greenhouses are dedicated to lettuce, which are grown in round fibreglass pipes using classic NFT techniques. They are the same fibreglass pipes found in the oilfield industry.
“A lot of people use PVC channel, but the reason I use these pipes is simply because they’re cheap and readily available,” comments Cooper.
One greenhouse is dedicated to seedlings. Seeds are started in oasis cubes, then transplanted into the NFT nursery system. As the lettuce grow larger, the pipes are moved further apart to optimise space and air circulation.
“In greenhouses we’re selling sunshine,” comments Cooper.
The main lettuce variety is Ostinata RZ, a Boston ‘butterhead” variety that produces a tight head during winter, but tends to develop more as a leaf lettuce in summer.
“I shade it, I cool it, I do everything I can, but it’s still more a leaf lettuce in summer,” Cooper explains. “But my customers have been with me a long time and they recognise that my product changes from season to season. It still fits their purposes.”
Young’s Greenhouses also grow baby lettuce and smaller volumes of red and green oakleaf, which are popular with chefs and restaurants.
The feed solution is a blend of well (bore) water, nutrient-rich wastewater from the tilapia system, and nutrient elements that use the Steiner formula as their basis. The well water has an abundance of calcium (90.95 ppm), bi-carbonate (274.18 ppm), no iron, and a hardness of 835.00 micromhos/cm. Chelated trace elements are pre-mixed for Cooper’s water.
The lettuce system operates independently from the watercress, which uses a weaker feed solution. The feed solution is manually tested morning and night, and adjusted to maintain a conductivity of 1500 ppm, and slightly higher in winter. During summer, the nutrients are added in the evening.
“It helps reduce tipburn, and puts less stress on the plants,” explains Cooper.
Until 8 months ago, tipburn and pipe scaling were major problems, but the installation of a Calclear computerised water conditioner near the well site has significantly reduced the incidence of tipburn, and seemingly eliminated scaling.
“My water is real hard here,” explains Cooper. “About once every month I had to put vinegar in the coffee pot to cut out the scale. I remember cutting a 1 1/2″ pipe that had been running for 8 years,” he added, “and I could hardly get my little finger down the middle of it.”
The evidence suggests that Calclear units lower the severity and incidence of tipburn by having a beneficial effect on xylem conductance. It not only improves uptake and transport of calcium, but also seems to improve its utilisation in plant cell development (Dr Lynette Morgan, 1998).
“It’s not long enough to know what the pipes are doing,” says Cooper, “but there are less stoppages in my spaghetti tubes, and my coffee pot is working okay.”
Four greenhouses are dedicated to watercress, an unusual crop for Texas that has found a ready local market. The NFT growing system was initially developed by son Kyle as a project at Agricultural school, where he also learned to grow and manage watercress as a crop. The system is unusual in that it looks more like an extraordinarily long flood and drain table at first glance, rather than a series of tables, each slightly lower than the next. Nutrient solution is allowed to cascade from one growing level to the next, until it is captured at the lowest end of the growing system, then recirculated back to the top end. Like the lettuce system, the feed solution is drawn from well water, blended with fish wastewater, and adjusted using nutrient elements to maintain an optimum conductivity of 1100 ppm, and slightly higher in winter.
The aquaponic system is a recent addition to the family farm, and still a learning experience. The rearing tank is large enough to raise 15,000 tilapia, but not large enough to provide enough wastewater to feed the lettuce and watercress all year round.
“I read that some greenhouse growers were raising fish, so I built a tank, and made it big enough so it would make a good swimming pool if the fish failed,” says Cooper.
Initially, the system was a true recirculating system, but Cooper soon discovered he had either too much wastewater, or not enough to feed his greenhouse crops, depending on the stage of growth of both the tilapia and greenhouse crops.
Although still a closed system, the tilapia system is plumbed between the well and the greenhouses, with the wastewater used to supplement the make-up water.
“As the nutrient begins to build up in the fish tank, I open a valve and let the wastewater supply the greenhouse crops,” explains Cooper.
The tilapia system uses a farm-made sand and biological filter to convert ammonia and to remove suspended particles and solids from the water. The solids are backwashed from the biofilter using air pressure, and then used to fertilise the pecan trees. So nothing is wasted.
The rearing tank water temperature is kept at 80°F (26.7°C). Cooper reports that tilapia will tolerate poor quality water conditions, and can be raised in high densities. What algae does grow in the tank is quickly eaten by the fish, although their main food source is high protein commercial pellets.
The Pests & Diseases
Cooper experiences few pest and disease problems, which he attributes to good sanitation practices – the pipes are cleaned after picking, all plant matter is removed from the greenhouses, and the grass below the tables and surrounding the greenhouses is strictly manicured.
“The only trouble I have is pythium in the summertime, when the water gets warmer,” reports Cooper. “We take care of that using hydrogen peroxide (3-4 ppm). It does a wonderful job,” he says. In watercress, the main pests are aphids, and occasionally grasshoppers, which are dealt with using biologicals.
“Fish are susceptible to so many chemicals,” observes Cooper, “and we also have to think about the people working inside the greenhouses,” he says.
Both the lettuce and watercress are marketed to wholesale customers in Dallas, and some ends up as far away as Houston and New Orleans. With fresh-cut products now dominating the local grocery store shelves, Cooper’s high quality lettuce is snapped up by what he calls the ‘white tablecloth’ market such as restaurants, “where the chef cares about what goes on the plate”. The watercress and tilapia are marketed to both grocery stores and the upper end of the market.
Cooper believes there will always be a market for high quality lettuce.
“I don’t market it as pesticide free or organic,” explains Cooper, “and my boxes carry the label ‘hydroponics’.”
Young’s Greenhouses has been serving many of the same customers since 1980, and rely on brand recognition to promote their high quality produce. The lettuce and watercress are harvested four times a week, cooled, and delivered farm fresh to the customer who is prepared to pay a little more for a premium product.
The Young family have planned well for the future, and a fifth generational link to the farm seems assured. According to Cooper, there has been a decrease in head lettuce in grocery stores over the past few years in the Dallas-Fort Worth area, because of a surge in pre-pack salads.
“That’s why we moved into watercress and some of the baby lettuce,” Cooper explains. “We have also moved away from grocery store markets, and into the higher-value ‘white tablecloth’ markets.
“In the current market environment, my lettuce is stable, and the watercress and baby lettuce markets are still expanding. And more people are calling on me for fish than I can supply.
“There will always be a market for high quality produce, where the corporate tigers cannot compete on service or quality,” assures Cooper.
After 20 years since he grew his last tomato, Cooper is going to plant another crop of tomatoes, using a closed hydroponic system. “This time we are going to take care of the pythium with a little hydrogen peroxide,” he says.
In spite of corporate consolidation and higher labour costs, life still looks pretty rosy down on the family farm.