Try your hand at sustainable gardening with at-home hydroponics

Try your hand at sustainable gardening with at-home hydroponics thumbnail

Plucking ripe tomatoes, cucumbers, and heads of lettuce all year long in your apartment sounds like a dream to both a couch potato and a houseplant hobbyist. Thanks to hydroponic cultivation, this is possible, even without playing hours of Stardew Valley or Terrarium.

Hydroponic cultivation, a method of growing crops in nutrient-rich water instead of soil, isn’t a passing fad. According to one recent market estimate, the commercial-scale industry was valued at $9.5 billion in 2020 and could double by 2028.

There are now a growing number of DIY hydroponic kits, ranging from simple, bare-bones models to sophisticated, minimalistic designs. And they seem to have gained popularity with consumers during the first year of the pandemic; AeroGrow, which makes the AeroGarden-branded hydroponic sets, saw revenue increase 107 percent from the third quarter of 2020 from a year earlier.

But, is the amount of electricity required to grow and harvest the produce without soil in your kitchen more sustainable than traditional or commercial cultivation? The answer is probably no for some vegetables.

Certain crops fundamentally are better suited for at-home hydroponic cultivation than others–meaning you shouldn’t have to put in months or years worth of resources before you see the fruits of your labor.

Often the first thing that people ask Angelo Kelvakis, the research and development director and master horticulturist at hydroponic gardening company Rise Gardens, is whether they can grow an avocado tree in their home.

“[Avocado trees] are difficult to grow, take years to cultivate and require tons of water, light, and other resources.” he explained.

He states that produce almost entirely is made up of water. This means that fruits, such as berries, need a lot of water throughout their growing period. The problem is that fruiting plants require space and attention. Commercial-scale operations have a better chance to succeed because they have more space, plant-specific cultivation methods, and enough workers.

[Related: Build a DIY garden you can bring on the road.]

Kale, for example, can be difficult to grow in a hydroponic setup. It can grow up to three-feet tall and several feet wide in soil fields. This concern can be countered by growing dwarf varieties of these crops that have manageable root structures.

“Issues arise when people want to grow non-dwarf varieties,” he explains. “These plants will quickly outgrow indoor systems and can cause problems with plumbing, growing into light fixtures, and leaf litter scattered around your unit.”

Experts say that crops like tomatoes, smaller leafy greens and some herbs grown at home in hydroponic settings require less water than those grown in the field.

“Greenhouse-grown produce can be 10 to 15 times more efficient compared to [produce] grown in field conditions in terms of water use efficiency,” says Murat Kacira, the director of the University of Arizona’s Controlled Environment Agriculture Center. “For instance, it may take about a gallon or less than a gallon of water for a head of lettuce to be grown in a [commercial or at-home] greenhouse system, compared to 10 to 15 gallons of water per head of lettuce grown [in a field.].”

Hydroponically grown tomatoes also appear to be more adept and efficient with their water intake than tomatoes grown in soil, according to a study published last year in Scientia Horticulturae. Hydroponic tomato plants experienced less evaporation. The hydroponic plants consumed water more efficiently than those grown in soil, yet produced roughly the same quality and quantity of fruit.

But what about the electricity consumption to keep your grow lights on and your water circulation pumps running? The sun is the best source of energy. Experts in hydroponics say that you don’t need grow lights for hydroponic setups. You can still use natural sunlight, such as microgreens, which can grow with the ambient light from your home.

“The sun is the best thing. That’s why all plants [evolved],” say Kelvakis. Additional lighting is required for plants that have long photoperiods, or require more intense sunlight than the area has.

However, air conditioning is another consideration for the electricity gobbled up by indoor hydroponic crop cultivation. Even commercial growers “haven’t really cracked the code” yet on the energy costs, says Jacob Pechenik, co-founder of at-home hydroponic system company Lettuce Grow.

“You’re powering all the lights, but then you also have this hot space you need to cool, so you have to get air flow and circulation and that’s when the power requirements become very high,” Pechenik adds.

But with indoor hydroponic systems, if your AC unit is working well for you, you won’t need additional cooling power. Kelvakis says.

Other environmental factors must be weighed against the significantly greater energy requirements for indoor cultivation, according to Deane Falcone (Chair Scientific Officer at Crop One), a vertical farming company.

He explained that the increasing extreme weather conditions such as prolonged heat waves, major rainstorms, and inundations associated with climate change do not directly impact indoor crop cultivation like it does on traditional crops.

” This level of uncertainty and variability in weather [with outdoor growing] must be balanced with the reliability we get from indoor growing, including in our own homes,” says Falcone. “So you’re probably not going to be providing all the sustenance for your family from your indoor growth system, but you’ll always have something of decent quality.”

[Related: Vertical farms are finally branching out.]

Growing crops indoors eliminates a plant’s exposure to pests, diseases, or polluted soil. Outdoor crop cultivation is less efficient because of this.

This type of exposure can have an impact on both the edibility of the produce and its attractiveness, Falcone explained. Falcone said this is an important factor to consider when trying to reduce food waste. For example, he explains that low-to-no bacterial concentrations on lettuce leaves grown indoors mean “adding two to three weeks to the shelf life, so you’re probably going to [have time to] finish consuming it.”

” Crops grown in [hydroponic] farming systems or in a horizontal [hydroponic] farm system are currently produced under optimized conditions,” says Kacira. “The yield outcome, as well as the quality attributes are maximized meeting the expectations of the consumers in terms of the size, the color, the texture, the flavor, the nutritional content, everything.”

However, Kacira says while the electricity usage per plant might be similar between a home and commercial set-ups, “what you can achieve with the produce coming from a commercial setting may be slightly different in terms of the yield and quality attributes.” A home grower’s experience and attentiveness will also play a factor. If you are determined to set up indoor hydroponic gardens, now is the time to make a commitment to your green thumb.

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