Hydroponics Without the Hype

SPIN farmer Mary Ackley gives President Biden a tour of Little Wild Things City Farm in Washington DC in March 2021.

While not new, hydroponics has gone through a myriad of permutations over the last decade as high-tech entrepreneurs and the big money that funds them set their sights on local food production. Vertical, indoor farms has exploded, in many cases becoming synonymous with urban farming.

Here’s what having money to burn produces: millions of square feet of growing space, six figure greenhouses on grocery store roofs, seven figure skyscraper farms, fresh “living” greens kiosks in grocery aisles, green walls and robot farmers. Hyper-local. Clean. Zero pesticides. Up to 390x more productive than field farming. Uses up to 95% less water than field grown. These are some of their marketing messages. Enough consumers are buying in to make it a multi-billion dollar industry.

Their big figure R&D budgets have quickly allowed them to expand their crop repertoire beyond high-end lettuces, microgreens and herbs. Celery, cucumbers, flowers, peppers, strawberries and tomatoes are now part of their product mix. The industry won a major victory last year when the USDA ruled that hydroponics can use the organic label.

It remains to be seen how much staying power any of these high-tech engineering feats will have, but simpler and less expensive versions of hydroponics have been around a long time that work well at backyard-scale and accomplish the same end: growing food where you wouldn’t otherwise be able to, whether that be in cities, on a sloped plot with rocky soil, a concrete parking lot or restaurant basement.

Hydroponic operations can vary widely in terms of how they are structured, but what defines them is their use of water-based nutrient solutions, with or without the use of a medium like perlite and noir/peat moss, to provide support.

Whether you grow in soil or in a hydroponic system. the nutrients are the same. In soil, plant roots take up an aqueous solution of mineral ions (NPK plus micro nutrients) to nourish growing tissues. They hold onto some of the water and transpire what they don’t need. In hydroponic systems the plants use the same mineral nutrients, and the roots suck them up the same way.’

Hydroponics is different from soil in that you don’t have to bring in organic matter to amend the soil and add minerals. You use formulaic blends that you match with water, such as Premium Lettuce Mix.

Hydroponics also requires a facility of some type to house the operation. It does not have to be elaborate and can be fitted into a space you already have, like a spare room, garage, basement or small greenhouse. Where the setup is sited depends on whether natural light or grow lights are used. You can spend as much or as little as you can afford on gear like lights and shelving.

Hydroponics can be a standalone operation or be combined with outdoor growing. Either way, the same small plot intensive growing and business principles are applied to both. That means you need to decide what crops and how many relays you’ll do per season. You can also use standard SPIN-Farming revenue targeting criteria to establish benchmark revenue and yield figures, workflow management and post harvest protocols.

So while the growing techniques might be different, other aspects stay the same. The big question is whether you want to have a standalone hydroponic operation, or one that compliments your outdoor production. There are a lot of benefits to having both types of operations, which might not have to be implemented at the same time. You could extend your growing season with hydroponics, which “weather proofs” production and can greatly help with maintaining consistent weekly sales. The trick is finding the right balance between the two types of production without losing your focus in either realm.

You also need to think about presentation at market and whether to use the hydroponics method as a selling point. This is where building on the efforts of the large-scale innovators might come into play since they are breaking ground and establishing premium markets for this kind of crop. You might even impress a VIP by showing just how big an economic stimulator small farms can be.