The basics

When we look at the growers who are producing at least 80% of their produce hydroponically over the past three years, the numbers have remained relatively steady. Just under half of the growers surveyed are in this range.

This year, the middle range (50-79%) was slightly higher than in the past, jumping from 3% to 11%, while the 10-49% range was slightly lower, dropping from 51% to 42%. As last year 65% of respondents stated they were planning to expand their hydroponic production, these numbers show that growers are indeed following through on those plans.

From 2015 to 2017, growers who grow less than 10% of their crops hydroponically still make up about a fifth of the total group. Some of these growers have started small, with the hopes of expanding in the years to come, while others are using the hydroponic systems on a smaller scale to supplement their main operation.

While only 46% of the growers we surveyed are growing hydroponically, most growers who try this growing method are open to expansion, a trend that's continued since our 2015 study. Again this year, nearly two-thirds of respondents stated they’d like more hydroponic growing space in the next 12 months.

Jesse Adkins, owner of 10-year-old hydroponic operation Hurricane Creek Farms in South Carolina, says their expansion is dependent on how a new strawberry crop, due to be harvested between October and March, does. “If they do what we anticipate, we may expand again and get one more house,” he says. “We say we’ll never do it again, but opportunity always presents itself and you jump on it.”

Andrew Spollett, vegetable production manager at Bartlett’s Farm, also said that expansion is a possibility. “We currently do not have a plan to expand our hydroponic operation, but I certainly think it is something that we will revisit given the success that we have had thus far,” he says.

Dave Tuttle, owner of Riverside Farm Stand and Greenhouse, which was founded in 1743, says that, at 69 years old, he’s not sure he’ll be making any significant expansions in the coming years; what they have now has worked for them for the seven years they’ve been growing hydroponically. “I want to keep up with the demand, but boy, it gets to the point where you just have to say, ‘I think we’re going to have to stay where we are,’” he says. “[But] I may build another vertical system to give me more salad green capacity.”

Adkins says that their growing months are strategically timed both to fit with weather constraints and consumer demands. “We do lettuce year-round, but as far as producing tomatoes, bell peppers and cucumbers, we basically pick those from late October to about the first or second week of July, clean out, and start all over again,” Adkins says. “[In July] tomatoes get really cheap because of most people’s home gardens and outside growers are coming in then. We’ve been picking tomatoes for six or seven months at that period, and it’s time for us to clean out and start over. It works well with our planting schedule and harvest because we’re growing out of season with everybody else … and getting a pretty good price for those out-of-season months.”

For Bartlett’s Farm, a grower in its second season of growing hydroponically as a complement to the other systems in its 35 greenhouses, the goal is to grow its lettuces and herbs year-round, but they had to shut production down for a few months to expand the number of benches and re-engineer the plumbing.

One of the biggest challenges for Riverside Farm Stand and Greenhouse is labor, which influences when they grow. “One of the reasons why I grow in the wintertime is because I keep two people year-round because they’re really great workers and I don’t want to lay them off in the winter,” Tuttle says. “That’s one of the reasons why I do hydroponic [crops] and grow [kale] in [a hoophouse] in the ground in the winter.”

Non-hydroponic growers

Photo Courtesy of Bartlett’s Farm

The number of non-hydroponic growers planning to convert to hydroponic growing in the next 12 months remained consistent — about 10%. Among the biggest obstacles to switching to this type of system are cost, lack of knowledge and satisfaction with their current growing system. While cost was the biggest obstacle for many growers – 46% chose it as an obstacle in 2016 — 7% fewer growers chose it this year. Five percent more growers reported that they prefer traditional organic methods in 2017 than in 2016.

Andy Teraud, the owner of a non-hydroponic operation called Acorn Creek Garden Farm near the city of Ottawa, Ontario, says they prefer to use an artificial soil medium. He acknowledges the growing popularity of hydroponics, but believes soil-grown produce tastes better, especially when grown in a greenhouse. “[Hydroponics is] going to be the dominant system of growing crops in the greenhouse because on a factory scale, it’s the easiest,” Teraud says.

Words of (hydroponic) wisdom

Are you one of the growers considering a hydroponic production system? These hydroponic growers have a few words of advice and insights to take into account as you make your decision.

Hydroponic systems require a significant amount of capital to build and operate. Also, if you are a traditional farmer, it takes a significant amount of re-education for hydroponics — maybe more so than a “green” farmer. In addition to everything else a farmer has to be, add a geek to the list. Knowing how the systems operate and how to work with them is needed. Hydroponic systems need a significant amount of attention; if you are not careful and attentive you could lose two months’ worth of production all at once, maybe within an hour or two. Do the research for your market area, be sure it can support this type of operation. Be ready to invest the time, money and effort, it takes a lot of all three. — Joyce & Jerry Conner, Four Oaks Farm in Wirtz, Virginia

Do your homework because the nutrition requirements of different vegetables are going to be different and then you’ve got totally different water requirements than you would for other crops you grow in a greenhouse, like bedding plants. Doing your homework is the most important thing to do. —Jesse Adkins, Hurricane Creek Farms in South Carolina

Learning how the hydroponic system functions is not as difficult as it may seem, and you do not have to be completely tied to the computer. Initially, I was worried that I would need to constantly check on the computer but that hasn’t been the case. Also, get a separate EC/pH probe so that you can be sure the computer’s probes are reading accurately. — Andrew Spollett, Bartlett’s Farm in Nantucket, Massachusetts

You have to learn more about how plants grow and what they need. Get advice from your extension people, people from colleges, get advice from other hydroponic growers — don’t just go into it blind because you’ll have an awful lot of errors if you don’t go in with some education. I would set myself up differently now than I did when I first started, so really plan well, look at other operations and really learn a lot about hydroponics before you get into it. It’s great to do but it’s quite a learning curve. — Dave Tuttle, Riverside Farm Stand and Greenhouse in North Berwick, Maine

You’ve got to pay more attention to what you’re doing, and the cost of the input is higher too, but you can certainly get some good deals out of it. It’s a tradeoff between higher costs up front and higher levels of management, but you can get better stuff because you’re fertilizing every time you water, whereas in the field, you only fertilize every time you irrigate. I think you can get some better-tasting, better nutritious plants too because you’ve got complete nutrition on the plant. --Dave Tyznik, Planter’s Palette in Winfield, Illinois

Tomatoes and lettuces have traditionally been popular hydroponic crops; about two-thirds of growers produce one or both of them, according to this year’s results. Tomatoes are on the rise, as only half of respondents were growing them in 2016. Beefsteak tomatoes saw a significant jump from 27% last year to 43% this year, just about back up to what we saw in 2015. Cherry tomatoes increased 6%, while two other tomato types — tomato on the vine and heirloom — were up slightly.

The popularity of hydroponic lettuces and leafy greens has remained fairly consistent over the years. This year, however, specialty leafy greens like bok choy and Swiss chard were up 10%, while spinach was down 7%. Perhaps growers are looking to diversify their growing mix to offer something different than their competition.

Cucumber production increased by 12% to 42%, also returning to 2015 levels. Root crops like beets and radishes doubled last year’s levels, and turnips, a new choice this year, are being grown by 4% of growers. Also new this year were mushrooms, other berries and pumpkins, all of which were being grown by a handful of growers.

Overall, we see that growers are growing a wide variety of crops in different hydroponic systems. Some growers, like Adkins, are dabbling in unique crops. “We do tomatoes, bell peppers, cucumbers and lettuces, [but] we’re also doing turmeric and ginger,” Adkins says. “This fall we’ll be starting a fourth greenhouse with strawberries.” Adkins says they’re using a different growing media for turmeric and ginger, but are still able to grow them hydroponically alongside their other crops. “We saw it as an opportunity,” he says. “We have lots of customers that are buying [the turmeric and ginger] now since we started growing it, and we’re expanding it a little more this year to keep up with the demand.”

Tyznik is growing lettuce, peppers and cucumbers in their double poly hoophouse, experimenting with onions in modified bato buckets and thinking about trying cantaloupes.

Conner currently uses an NFT system for the lettuces, greens, microgreens and herbs that they grow at their exclusively hydroponic operation. “We plan to install a bato bucket system in the near future for planned additional [vining] crops,” he says.

Nutrient film technique (NFT) systems are still the most commonly used for hydroponic production, with just over 38% of the total growers. Considering that NFT is a system that’s well suited to lettuce crops, it makes sense that many of the 65% of growers who are producing lettuce would use it. Raft, or deep-flow technique (DFT) is also a prevalent system for lettuces and greens, and comes in at 23%.

Slab or hanging gutter systems have been trending down over the past three years as others, such as vertical systems, are trending up; this year was the highest we’ve seen for vertical systems, 18%. Perhaps growers are focusing more on higher value crops like greens, microgreens and herbs that grow well in NFT, DFT and vertical systems.

About a fifth of growers are still using DIY systems, while about double (up from 5% in 2016 to 11% in 2017) report using a system that’s not listed.

Adkins says that Hurricane Creek Farms uses several different systems for their crops because of the varying plants? needs. “We found that the greens work best in a raft system for us, [but] we do a few things in an NFT system, like arugula that requires more oxygen than we can get into the raft system.”

Tuttle built his own vertical systems for their hydroponic cucumbers and greens. “I built a vertical system in one of my hydroponic houses to maximize the space and that does very well,” Tuttle says. “We grow greens in a vertical system [too] and [use] supplemental light in all the different layers.”

In our 2016 report, many growers wrote in that they were using a substrate that wasn’t listed — wood chips. This year, 10% of growers reported wood chips as one of their substrates of choice. Thirteen percent fewer growers are using rockwool, while slightly more (6%) are using perlite than in 2016. Besides a slight increase in the use of peat-based cubes, growers’ substrate use has remained fairly consistent.

At Four Oaks Farms, Conner says they use rockwool for all seeding except for their microgreens, for which they use either burlap or Sure-to-Grow cubes. Once they set up a bato bucket system, they’ll use perlite for their vining crops. Bartlett’s Farm uses Horticubes for germination before transplanting them into the NFT channels. “Our rep at CropKing recommended the Oasis cubes and they are working well for us,” Spollett says.

Pest and disease pressure is still at the top of list of challenges growers face when growing hydroponically — or in most other types of cultivation systems. Maintaining a proper nutrient balance was the next biggest challenge, which may be why we’re seeing more growers preferring to buy in a ready-made fertilizer mix rather than mix it themselves.

“Hydroponics requires constant monitoring to ensure plants remain healthy,” Conner says. “The winter offers several additional challenges with respect to the reduced amount of sunlight, and environmental challenges when the greenhouse remains ‘closed’ for several days at a time” such as during the holidays.

Tuttle weighed in about the challenges of learning soilless growing after decades of growing in soil. “You really have to know the plant physiology because you are supplying everything for that plant: the light, the cooling, the heating, the CO2, all the nutrient needs, all the water — it has to be very fine tuned in order to really have a successful crop, and I like the challenge of doing that,” he says. “But you’ve got the advantage of being able to grow during the wintertime and nobody else is around so you have to come to me. There are very few hydroponic places in the very southern part of Maine so I’m bringing lettuce and herbs and salad greens to farmers markets and to restaurants that nobody else has so it definitely has its benefits.”

Photo Courtesy of Dave Tuttle, Riverside Farm Stand and Greenhouse

The top insect pest is aphids again this year, but we saw a big shift in some of the others. Thrips, the second most prevalent pest in 2016, was down a whopping 21%, which dropped it to fourth. Spider mites and whiteflies decreased just under 10% each, while we saw an increase in caterpillars/larvae. Mealy bugs and shoreflies were new additions based on last year’s write-in answers, and a combined 8% of growers found them very problematic.

Fungus gnats used to be at the top of Spollett’s list. “Last year I struggled with fungus gnats, but this was due to algae growth on the benches,” he says. “By improving the drainage system and reducing the amount of light that comes in contact with the solution, we were able to eliminate the fungus gnat issue.”

Adkins says that the biggest challenge for Hurricane Creek Farms has been learning to treat insect infestations with different methods than they would ornamental plants. “You are dealing with an edible product, whereas with ornamentals you could use some things that you couldn’t [necessarily] use on vegetable crops,” he says.

The biggest drop in disease was early and late blights (Alternaria and phytophthora, respectively), which halved their numbers. Powdery mildew was up 6%, while downy mildew was down that same amount. Pythium was down 10%, while tip burn, a new option, was a top concern for 14% of growers.