Been talking a lot about plants and pastures, and the question on everyone’s mind is probably why (at least, it’s the question on my mom’s mind). Writers research the strangest things for the purpose of developing a world and characters that feel real. It doesn’t matter how fictional the story; a little reality engages readers that much more. So when I write a post about hydroponics, it’s for all the writers like me who decided they wanted a planet made of metal.
It also just blows my mind how awesome plants are. When I was in elementary school, my class visited a hydroponic farm, which is a farm with no soil. Just water. And I’m not talking coral or seaweed, I’m talking ferns and lettuce. It seemed impossible until I wandered around a facility that practically grew a jungle with tubs of water. I took this method for the metal planet I mentioned above, but there’s actually a lot more to the process than sticking green stuff in a bowl of water. Fair warning: you might read this and want to grow a hydroponic garden (I’m currently resisting the urge).
What’s Needed
As stated above, hydroponics don’t work if you just throw a plant in a bucket of water. This system of growing has to fulfill the same two necessities that soil does: nutrients and structure. Growers have been finessing the process for years and what they have found are three consistent elements. First is a waterproof reservoir which holds a nutrient solution made of water and fertilizer (Baras, pg 13). Second is a growing area divded by trays or pots that gives plants the structure needed for root growth (pg 14). Third is a growing medium or fertilizer. What’s important to note is that hydroponics fertilizers have all the nutrients needed for a plant to grow rather than one or two like soil fertilizers (Baras, pg 15). Usually hydroponics are grown indoors, so other necessary elements would be lamps and ventilation. The list gets longer as you have to create a climate controlled space that lets oxygen reach the roots and keeps pests away.
It is possible to drown plants which is why substrates are usually introduced into a system. Things like stone wool, peat moss, and clay pellets provide a pseudo-soil that adds structure, retains water, and lets oxygen reach the roots (Baras, pg 24-25).
Irrigation is another element that requires some discussion. It seems like you would need a lot of water in order to run a hydroponic garden, but that’s actually not the case. Depending on the growth system and irrigation, the same nutrient mixture can be recirculated, constantly providing plant growth. There may be a need to replenish, but it won’t be as dire as watering the garden once a day.
Just as ensuring soil remains nutrient, the water solution must remain nutrient and well-balanced. Usually growers use meters that gauge the concentration of fertilizers, pH levels, the amount of light, and temperature (Baras, pg 35, 37). Yes, these all factor into growing even though it changes for each plant. Seems a little tedious but could offer that smidge of reality that’s so necessary to fiction.
Growing Systems
Hydroponics are actually perfect for novels because they have more dimension than grass on the ground. Most hydroponic gardens I’ve seen are in a big box, but there are towers, elaborate piping, and ferris wheels. What makes the difference between each is what grows well and where. The plant, the location, the maintenance, the ease of use, and the upkeep are all factors that determine which system is the best (Baras, pg 39). In the case of fiction, we have the opportunity to mix, match, and modify.
- Hydroponics in a Bottle (Baras, pg 42) – This is the one I might try either this year or when I move out (pretty sure Mom doesn’t want a jungle in her house). Using an opaque bottle with a thin neck and wide body, you can grow leafy greens like lettuce and herbs like basil without any electricity or complicated irrigation system. It’s the simplest form of hydroponics. The bottle is the reservoir and growing area while the growing medium is poured in with the water. The only maintenance is ensuring there’s enough water in the bottle and that it’s well supported in case the plant gets heavy. Substrates like stone wool are used to keep the primary plant from falling into the drink.
- Floating Rafts (pg 50) – When thinking about hydroponics, this is the method that comes to mind; it’s the first one I ever witnessed. A large waterproof box acts as the reservoir while a styrofoam sheet with pockets for small pots is the growing area that floats on top. This has even less maintenance because the roots are submerged. Plants that require less oxygen for growth are best suited for this system, which includes leafy greens and herbs. Air filtration systems can be added in order to oxygenate the water for different plant life.
- Wicking Bed (pg 60) – This one uses a phenomenon dubbed capillary action, where water flows upward thanks to surface tension and adhesion (pg 60). The growing area sits above the reservoir with a cloth or burlap barrier between the two. One pipe allows water to go in while another pipe drains excess. The seeds are plants in a substrate in the growing area, water seeping upwards via the cloth. Again, kinda weird yet interesting from a science perspective. Other than herbs, wicking beds can handle short flower crops like strawberries.
- Nutrient Film Technique (NFT) (pg 69) – Here comes the more popular and extravagant piping method. NFTs are able to grow a lot with little; a small reservoir pumps water through constructed channels which are the growing area. This method has the possibility of recirculating the growing medium solution. The channel length, channel size, slope of the channels, and flow rate all determine the amount that can be grown and how well the water moves through (Baras, pg 70-71). Each plant, usually an herb or strawberry, does have a little pot that holds their small roots in place while water passes and drops off nutrients.
- Top Drip or Dutch Bucket (pg 83) – Time to bring in the large flowering crops. A Dutch Bucket is a literal bucket that has a small stream of water for each plant. The water moves down through the substrate, usually clay pellets, drains out the bottom into the larger reservoir, and gets pumped back in to follow the same course. At least, that’s how I understand it. This method usually includes a trellis which is a tall structure that holds the extensive system of flowers and leaves that a plant like cucumbers will grow (pg 91). It’s rather impressive, but restricted in how many you can grow in one bucket.
- Flood and Drain (pg 99) – Operatation instructions are in the name. Water flows from the reservoir into the growing area, flooding the plants. The excess drains into the reservoir and it repeats at given intervals. This is the one method listed that can efficiently grow anything. Similar to how the plot of land and environment determines what you grow in soil, pot size, pot material, substrate, and grow bed size are the variables you adjust in order to change what you grow (Baras, pg 100-101). Otherwise, it’s very simple.
- Aeroponics (pg 106) – Lots of plants make oxygen but not without using some to grow. Aeroponics has a “floating” growing area that’s watered by a mister. If you think of a sprinkler, that’s basically what’s happening inside the reservoir under the roots. It provides a mix of oxygen and water, but there is the risk of equipment failures leaving roots unwatered (pg 107). Other than that, it’s a self contained system where the water is reused to spray the plants from underneath.
Most of these methods, and others not listed or imagined, can be trasformed into vertical gardens. Rather than taking up a large surface area, gardens can be stacked or planted horizontally. Aeroponic gardens usually have a tall hollow tube that allows roots to get sprayed evenly from within. The Dutch Bucket can be stretched into a drip tower with water running down a long vertical track. TV shows frequently have planters on tables, but these can be swapped for flood and drain systems and stacked to created racks of plant life.
Something to note is that clear tubing and bottles are a no-no if at all possible; this prevents algae and other particulates from growing in the tubing and causing a hassle. Tyler Baras, a hydroponics grower, blogger, and speaker (I’m just as surprised as you that that’s a thing) would paint clear containers in a way that there’s a small strip that allows you to see how much water is in the reservoir. Black tubing or anything opaque is also suggested. Just watch out for the system getting hot because hot water and plants don’t mix.
Plants that Work Well
With all this reading, I figured I’d find some bold red letters stating that one plant or another can’t be grown with hydroponics. Seems that’s not necessarily the case. I do think someone would have a hard time growing a tree since their root systems are so pertinent, but many crops, vegetables, herbs, and such can thrive in a hydroponic system. The issue is making sure you have a big enough growing area with enough structure for the plant you’re growing.
Final Thoughts: There’s More than One Way
Tyler Baras is a hydroponics expert, and his consistent rule is experimentation. The crop, the build, the irrigation, the nutrient solutions. Every variable in the process can be adjusted and reoriented to fit a need. The only restriction is general rules of growing like providing enough light, oxygen, and room to grow.
Hydroponics can be an interesting backdrop, a cultural piece, a career, or a plot point in a book. However you design it, just make sure to keep key characteristics of farming in mind. These small realities that seem restricting could actually add more depth and development to the overall story. Otherwise, have fun. Your imagination has room to play.