...And Now, For Those Who Don't Like Dirt...

“People are very open-minded about new things - as long as they're exactly like the old ones.”

--Charles Kettering

We like hearing people tell us after they have read the blog, or after having visited the house, that they’ve decided that they, too, want to raise chickens in their backyard, or put in a bee hive, or add some more raised beds and grow a few more vegetables… but the truth is, we are not so stubborn and pigheaded as to think that our way is the only way.  There are myriad options when striving for a higher degree of economic, social, and nutritional autonomy, some of which we reject for philosophical or moral reasons, some for practical reasons, and some because we simply haven’t heard of them yet.

Fairly typical hydroponic greenhouse setup -- lots of plants in small spaces

One system of which we have heard, but which we never plan to adopt, is hydroponics.  We get this question all the time, and since we’ve never addressed it before, we figured, heck, the hottest week of August is as good a time as any to discuss a system of growing things based entirely on water.

A preface before diving in, just so you know where we’re coming from – we rejected the hydroponic approach early on, mostly for the amount of effort involved in setup and maintenance.  If you decide it’s your cup of tea, hey, knock yourself out.

A lot of myths and misconceptions abound about hydroponics, mostly because so few people have ever gotten a hands-on “look-see” at a system based on hydroponic principles.  For starters, most people think of aquatic growing techniques as a modern invention; the truth is, the first book on growing plants without putting them in a soil bed was written by Francis Bacon in 1627.  Up through the 19^th century, “solution culture” was a fairly popular research project – there was still a medium of some kind (often crushed pebbles or charcoal), but no soil, just a mineral water solution.

Among the early discoveries by curious “solution culturalists” were the fact that plants grew better in “impure” water than they did in distilled water – early proof that there were numerous nutrients plants acquire from their root system other than merely water – and that there were specific nutrients involved.  The techniques developed in this early time frame are, in fact, still used today for much of the plant material that finds its way into teaching botanical laboratories.

In the early part of the 20^th century, a University of California at Berkeley professor named William Gericke coined the term “hydroponics” (after he found that his originally preferred term, “aquaculture”, was already in use to describe the growing of aquatic animals).  Gericke was the first to propose that hydroponics could be used for widescale agricultural applications, rather than merely as a research tool.  He stunned the observers of his day by growing an indeterminate tomato vine to the astonishing height of 25’ in his backyard using a mineral solution and no soil. 

Disney's tomato tree - any tomato plant can reach these dimensions
under controlled circumstances; tomatoes are naturally
perennial, provided they are not exposed to extreme temperatures.

Disneyworld has since topped this feat by hydroponically growing a famed “tomato tree” of massive dimensions.  More on the fabulous hydroponics at Epcot in a moment, we promise.

Aside from the newness myth (which we believe is a consequence of hydroponics’ essential alien-ness as it relates to most people’s experiences with growing plants), there are several misconceptions about the basic working design (and consequent advantages and disadvantages) related to the structure of a hydroponic growing system.

It’s not as simple as just sticking plants in a container of water.

There are two main categories of hydroponic systems, and a lot of variation within these two categories.  “Solution culture” is the most commonly envisioned setup – this is a system in which there is no growing medium other than the water/mineral solution.  “Medium culture” is still technically hydroponic, but the roots of the plant are supported by some type of medium – sand, gravel, rockwool, etc.

Within solution culture, there are three variations:

• Static solution culture (like a rooted pothos ivy in a vase on someone’s office desk, for example) where the plant is placed in a non-moving water/mineral solution.  Not at all common for large operations.
• Continuous-flow solution culture (where numerous plants have their roots maintained in a slow-moving but continuously moving) water/mineral solution.  Think here of a greenhouse with a series of big pipes full of running water, with plants stuck in holes cut at regular intervals on top of the pipes.
• Aeroponics where plants are grown on a supported platform with their roots dangling below, getting continuously misted by a mineral solution “fog”.  This is the newest of the solution culture methods, and according to many researchers holds great promise for increasing productive capacity of greenhouse growing worldwide.

 Within medium culture, there are two variations:

• Sub-irrigation where water flows through the medium from below.
• Top irrigation where traditional watering techniques from soil-based agriculture are used, and water seeps into the medium from above.

For each of these growing methods, the advantages and disadvantages are more or less the same, though the degrees of each may vary.  Advantages include:

• No need for soil or for soil treatments
• Water stays in the system and can be reused (lower water requirement, not higher, as is often believed by the uninitiated)
• Much easier to monitor nutrient loading (no need to do soil testing – nutrients are measured and added to the water, so you know exactly what the plants are getting)
• pH and other factors are easy to monitor
• No runoff pollution
• Can be integrated with an aquaculture system – nutrients from the plants can feed fish; waste material from fish in turn fertilize the plants

  

  Full hydroponic/aquaculture cycle.

• Year round production, since you are growing in a controlled greenhouse environment
• Pest and disease control are much more manageable (simply remove infected plants from the environment, and they cannot affect the other plants)
• Harvesting is easy – just grow your plants at levels where you don’t have to bend over very much

 Disadvantages include:

• Need a relatively large greenhouse
• Startup costs can be prohibitive – pumping equipment, specialized containers, etc.
• Need to be a specialist rather than a generalist – ie, you have to know exactly what nutrients are needed, exactly what pH levels should be, etc., for each of the different plants you are growing
• Needs much more monitoring than a traditional soil-based garden schema
• Lack of soil as a buffer means any short-term failures in the hydroponic system can be fatal to your entire crop in a very short time frame
• Verticillium wilt and other waterlogged plant diseases are much more common
• Different kinds of containments systems are required for different kinds of plants; switching from one kind of crop to another between seasons or years is much more complicated

 On the whole, we are thrilled that research is being done on how to increase the productive yield in the agribusiness sector while and at the same time decreasing the consumption of water and eliminating runoff pollution.  If the green fields of the corn belt were to be replaced in all those Google Earth pictures by a landscape dotted with glass-roofed hydroponic houses, nothing would make us happier.

However… it’s not for us.

Living With the Land - Epcot's boat ride through a hydroponic greenhouse.

In January of this year, we packed up the family and spent a week at Disneyworld in Orlando.   Naturally over the past eight months there has been disagreement about “the best part”, but for one member of Myrtle’s family, at least, the highlight of the experience was the “Living With the Land” exhibit at Epcot.  Disney has integrated a vast hydroponic and aquaculture laboratory with their theme park and dining facilities, and has basically hit a home run in the “future of agriculture sweepstakes”.  We still believe that small scale, market farm approaches are the best possible use of the world’s farming spaces, but… it is hard to argue with the successes of the hydroponic researchers who can grow the delectable dainties upon which we dined while we were there.

For most small scale growers, though, and particularly for families living on limited spaces and budgets, the time and capital commitments involved in “doing hydroponics right” are just too much.  We suspect if you did a cost-benefits analysis, market farmers with a few acres or more would probably come out way ahead of the curve in terms both of cost control and of production quality and quantity by switching to a greenhouse/hydroponic approach.  For folk with a day job, however, we are guessing maybe not so much.

We are looking forward to a return trip to Orlando some time soon, though.  The food was amazing.  If, you know, you’re into that sort of thing.  As Kettering noted, people are a little leery of things that are different.  Well, the growing method may be different, but hydroponic veggies are every bit as scrumptious as their soil-grown forebears.

Happy farming!