With rising concerns over food safety and sustainability, consumers and commercial growers are exploring ways to produce more food more efficiently, without relying on traditional farmland. In fact, some don’t rely on land at all, as these needs are driving interest and innovation in soilless growing systems like hydroponics, aquaponics and aeroponics to bring gardening indoors, all year long.

Indoor gardening is a billion-dollar industry, with 37 percent of Millennials and 28 percent of Baby Boomers growing indoors, according to Garden Media Group’s 2017 Garden Trends Report, Grow 365. This trend points to huge potential for retailers of soilless systems and supplies, but specialty stores dominate this market. Are IGCs missing out on ’ponics? Here’s what you should know.


What it is: Hydroponic systems use water to deliver nutrients directly to plant roots. Inert growing media like pebbles, clay pellets or rockwool can support plants while roots are submerged.

Products required: Greg Thiel, garden center division manager for hydroponics supplier Hydrofarm Inc., says, “Most garden centers already have at least 40 percent of what they need to get into hydroponics — seed starting supplies, trays and nutrients. Next, you can bring in lighting, and then small hydroponic units.”

IGC example: Dambly’s Garden Center in Berlin, N.J., launched an indoor gardening department about three years ago; hydroponics makes up half of it.

Space dedicated: Dambly’s sits on 10 acres, with 8,600-11,000 square feet of hard goods. Indoor gardening comprises 1,200 square feet of retail space and more than 100 linear feet of gondola space, plus displays.

Thiel recommends at least 12 to 16 feet for a dedicated hydroponic section. Don’t have the space? “Just dovetail it off of your seed-starting section, and then move four feet of lighting next to it,” he says. “You could do a small section of fans and pumps, or point customers toward the pond section.”

Why hydroponics?: Lured by year-round cash flow and new customers, Dambly’s started offering indoor gardening supplies because of one particular plant. “As [cannabis] becomes legal, somebody’s going to have to service that community,” says owner Harold Dambly. “Most of the industry wants nothing to do with it, but the reality is that it’s going to happen. There was only one store within a 40-minute drive from us that specialized in indoor gardening and hydroponics, so we created a department to capture some of that business.”

Typical customer: Dambly says 15 to 25 percent of hydroponic customers grow herbs or vegetables indoors. The other 75 to 85 percent grow cannabis. Attendees at Dambly’s indoor gardening seminars range from 20-year-olds to 70-year-olds, “and the 70-year-olds aren’t necessarily looking to grow vegetables,” he says.

Merchandising: “When we first started, it was a store within the store,” Dambly says. “We grouped all the hydroponic products together, because customers would only shop that area. As it’s grown, there’s been more cross-merchandising to get people to wander the store. There’s a lot of crossover products we sell already — rooting hormones, organic fertilizers, fabric pots and fiber pots. We also sell pond supplies, so a lot of the pumps, filters and aerators coincide with hydroponics.”

Buyers beware: “While lawn and garden distributors ship orders of $500-$700 free freight, hydroponic warehouses want $1,500-$4,000 for free freight,” Dambly says. Dambly’s is less than an hour from Hydrofarm East, which supplies most of its indoor gardening products, so he picked up smaller orders — which gave him opportunities to ask sales reps about the products.

Sales growth: Dambly’s indoor gardening department doubled in size annually for the first couple years, and now exceeds $100,000. Depending on your state’s marijuana laws, Thiel estimates that a well-run hydroponics section could see growth rates of 20 percent or higher.

Tip: “You have to have somebody champion it,” Dambly says. Thiel recommends looking to specialty stores to find employees with hydroponic knowledge.

Why aren’t more IGCs selling hydroponics – and why should they?: IGCs and specialty stores both struggle to market around the stigma, Thiel says. “Most people equate hydroponics with cannabis, but we’re trying to promote it as indoor gardening year-round,” he says. “Customers are asking garden centers to bring in hydroponics because they’re uncomfortable going to a specialty store.”

Hydroponics and aquaponics systems are a rare sight in most IGCs, allowing early adopters to set themselves apart.


What it is: Aquaponics combines hydroponics with aquaculture (raising fish) to create a symbiotic ecosystem. Fish waste supplies the plant’s necessary nutrients while roots oxygenate the water for fish. The main input is fish food, which is cheaper than hydroponic nutrients — a benefit for consumers but not for retailers. Aquaponic systems only use about 5 percent of the water required for soil gardening because water is recirculated (and doesn’t need to be drained and replaced frequently as with traditional hydroponics). Since water circulates more frequently in aquaponics, electrical requirements are more complex. Systems typically cost more and take longer to set up, but can be easier to maintain long-term.

Products required: Tanks, liners, filters, pipes, pumps, aerators, fish and fish food, and maybe heaters to maintain water temperatures. Tilapia are the most popular fish for aquaponics, but catfish, shrimp and even decorative koi will do – if temperatures are maintained.

IGC example: Waiahole Nursery and Garden Center opened in 2009, a year after the owner’s family started an aquaponic farm on an orchid nursery they acquired for vocational training. They focused on education first, and then started selling aquaponic and hydroponic supplies in 2013, which they only began promoting recently.

Space dedicated: Waiahole Nursery and Garden Center sits on three acres on Oahu, with one acre dedicated to aquaponic production (which supplies its farm market and restaurant). The aquaponic sales room houses about 200 square feet of specialty supplies like net cups, cloning domes and amendments. The Pond Yard has about 500 square feet of tanks, tubs, reservoirs and liners, and a 600-square-foot display garden contains fish and starter plants.

Why aquaponics?: “We saw how it could be beneficial in our island climate, where we have a long growing season, limited water and not-so-fertile land,” says Kathryn Hurd, manager of Waiahole Nursery and Garden Center — noting that it could work just as well in greenhouses in other climates. “You can grow more in less space, so it’s suitable for urban areas where people have small backyards or patios.”

Typical customer: “We see young families that are conscientious of what they’re feeding their kids and interested in doing an activity together,” Hurd says. “On the other end of the spectrum, we see a lot of retirees.”

Merchandising: Complete aquaponic systems sit in front of Waiahole’s retail entrance; they don’t contain plants, fish or water, but a banner above them depicts lush aquaponic gardens to give customers a visual. Outside the commercial aquaponic operation, a smaller display garden showcases kits and DIY systems.

Education: Waiahole hosts aquaponic seminars, tours and field trips — and even offers CARF-certified vocational training through its sister organization, Loveland Academy. “When someone buys a complete aquaponic system, they get a free seat in a seminar, because we want people to be successful, and a lot of other places that sell aquaponics don’t offer education,” Hurd says. Alternatively, customers who pay $25 to attend a seminar receive 10 percent off systems and supplies.

Sales growth: Though Waiahole only began promoting aquaponic systems and supplies recently, it sells an average of 1 to 2 complete backyard systems a month, ranging from $500 to $2,000 each. A typical day might see several hundred dollars in sales of miscellaneous aquaponics pumps and other parts.

Why aren’t more IGCs selling aquaponics – and why should they?: “Hydroponics is probably easier (for IGCs) to start with than aquaponics, and there are a lot of specialty indoor grow stores that already have it covered,” Hurd says. Still, “you’re definitely going to see aquaponics becoming more popular and relevant as people are more conscientious of where their food is coming from.”

The aquaponics systems at Waiahole Nursery and Garden Center supply the IGC’s farm market and restaurant.


What it is: Aeroponic systems suspend plants in a closed environment (usually some sort of tube), and then mist or spray the exposed roots with nutrient-rich water. Input requirements are the lowest of any soilless growing system, which is better for budget-conscious consumers than it is for revenue-seeking retailers.

IGC example: Finding IGCs expanding into hydroponics isn’t too rare, but very few IGCs offer and advertise aquaponics. When it comes to aeroponics, Thiel says, you’ll likely only find it online or in specialty stores. If you offer aeroponics in your store, we’d love to hear about it.

Why aren’t more IGCs selling aeroponics – and why should they?: Common challenges and concerns make IGCs hesitant to get hooked on ’ponics — from space requirements to cultural stigmas to promotion and education. Indoor growing systems don’t attract customers by sitting on a shelf in a package. Hydroponic, aquaponic and aeroponic units should be displayed growing fresh veggies, which requires space. But even small-scale displays require year-long maintenance and dedication — which means you need a staff that’s passionate and knowledgeable about it.

“If you’re not looking for a hobby, don’t get into it,” Dambly says of soilless growing. “It becomes a labor of love.”

What successes and challenges have you had selling hydroponics, aquaponics or aeroponics? Share your experience with us as we continue to cover this trend. Email editor Michelle Simakis at

Merchandising at Waiahole Nursery and Garden Center encourages home gardeners to consider aquaponics.
Waiahole Nursery and Garden Center supplements its aquaponics division with home growing seminars.

Brooke is a freelance writer living in Cleveland and a frequent contributor to Garden Center.