Hey Y’all! This is the first in a series of four articles on our early experiences in winter garden aquaponics. I originally wrote these articles for an aquaponics trade magazine in 2014. At the time we were experimenting with different methods of small scale winter aquaponics farming.
I am so happy and grateful to share our experiences in aquaponics with y’all.
I hope that you find these articles interesting and helpful in your own aquapioneer adventure.
My name is Spencer Curry, of Trifecta Ecosystems, Inc. We are an aquaponics farm and technology company based in Connecticut. We operate right on the line of the two coldest zones in our state, hovering between USDA Agricultural Zones 5b and 6a. That means our winter lows fluctuate from -15℉ and -5℉. This is far colder than your average aquaponics farm. Typically aquaponic farms are most popular in places such as Florida, California, Hawaii, and the Virgin Islands.
Over the next few weeks, we’ll lay out our exploits, trials and tribulations experimenting with growing in this cold environment.
What can you expect from this series on Winter Aquaponics?
Primarily this series has one purpose: help you learn from our mistakes. There’s no reason to end up making them yourself! We really want to speed up the learning curve for you as a new winter grower. That’s why I’m bringing you real and detailed experiences. I want you to learn from them. You’ll also follow the practical strategies, tactics, and moves that I’ve garnered out of those experiences.
What is Trifecta Ecosystems Up To This Winter?
As of the original writing of this article, we are 5 weeks into our 9 week Winter Community Supported Agriculture (CSA). This program is currently in its second year. The CSA program is a wonderful thing for farmers and their communities alike. It’s a simple setup, where CSA patrons will pay for their share of a seasons worth of produce upfront, at the beginning of the seasons.
The value proposition is like this: farmers receive a all cash upfront at the start of every CSA ensuring all their produce is spoken for. This totally eliminates wasted produce! Meanwhile, the customers themselves are paying for a seasons worth of the finest produce all at once. Thus freeing them of that burden for the coming months. In addition, generally a CSA share is worth far more than the weekly price breakdown would show. This means the customers are getting way more value for their dollar in exchange for paying upfront. CSAs make eating locally grown organic food affordable in a way that the big box stores simply cannot match.
We actually started our CSA program last year with a winter season program. As far as we know, we were the only Winter CSA program offering all local produce in town that season. To be fair there were other CSAs out there, but they sourced their produce from out of state or only had value added products most of the winter. No other farmer was harvesting fresh produce every week all winter long. That builds customer loyalty!
Using the power of aquaponics, we were able to provide our produce to seven families for fourteen weeks in a row! Now, our production capacity was still pretty limited at the time as we were only using my own personal backyard system. Not to mention we were still feeding ourselves too! My backyard aquaponics garden consists of 5 grow beds, 1 fish tank and 2 sump tanks, all made from IBC totes in the iconic Murray Hallam fashion. We have exactly 60 square feet of growing space in the system. Not exactly a ton by conventional standards, but we we were able to grow many fresh herbs all winter long plus the aquaponic staples, lettuce and kale. Our weekly offerings varied between rosemary, oregano, lavender, and sage. We also had some other random surprises like super-late harvesting strawberries and jalapeños.
Amazingly, we really didn’t take any special precautions to ensure our plants made it through the winter. We honestly were still extremely naive and simply didn’t know better. The greenhouse plastic of my backyard garden is only 1 layer thick and is not very well insulated. We didn’t even heat the greenhouse, we often had frost on the inside from the evaporation of the aquaponics system itself. I’d go and scrape it every so often, and it would basically be like a little snowfall on the plants. We found many of the plants, like the sage, rosemary and lavender seemed to enjoy their snowy blankets!
Heat in Winter Garden Aquaponics
The only real heat source in that entire system are 3 simple aquarium heaters, a 200 watt and two 300 watt units. These heaters provide enough heat to keep our system over the vital threshold of 55℉. This is the temperature at which the beneficial bacteria and other microorganisms in the system begin to go dormant. If you allow that to happen the fish waste stops being converted into nitrates at a high enough rate for your plants! It can also lead to too high ammonia levels for the fish. High ammonia and low nitrates! This is obviously catastrophic and something you want to avoid at all costs.Your water is your first concern in the winter. Keep it 55℉ or above.
The cool thing about maintaining this threshold is that your plants and fish get to benefit from the relatively stable temperatures as well. For us cold-weather aquapioneers, it is important to keep in mind this threshold temperature of 55℉ when deciding on what plants and fish you’ll be keeping. It is tempting to say you can keep tilapia or tomatoes growing year round. However, once that heating bill starts to rack up you will wish you had simply chosen cold weather crops and a more temperature tolerant fish breed.
Cold weather crops are much more tolerant to cold on their leaves than you might expect. We learned this from the small snow flurries our plants get every time I knocked frost off the greenhouse plastic. The key factor is that we keep the roots at or around that vital 55℉ threshold. The roots are sort of like the brain of the plant. The roots are the main sensors and trigger the release of hormones which affect the plant in major ways. If the “soil”, or in our case water, gets too cold, it will trigger dormancy or slow the plant’s growth. But, if you expose the roots to warm water temps you can trick the plant into thinking its not the dead of winter. In some instances you can avoid a dormancy stage altogether. If you can afford supplemental lighting you can uninterrupted growth cycles!
Sunlight in Winter Garden Aquaponics
We also found that light was a major factor in the slower growth in the winter seasons.
From a technical standpoint, the sun bathes the Earth in a range of frequencies of light, including Ultraviolet (UV) light. Some types of UV light are extremely harmful. Luckily our ozone does a pretty wonderful job of protecting us from these rays. However, the medium (UV B) and long wavelength (UV A) versions of UV light make it through our atmosphere. Of the two, we receive primarily UV A light. UV A makes up about 95% of all the UV that makes it to Earth’s surface. The remaining percentage of UV B is determined by the atmosphere, including cloud cover.
The most important factor of the ratio between UV A and B is the angle of the Sun to the Earth. The further you get from the equator, the less direct sunlight there is during the winter months. Here in Connecticut, we lose all UV B sunlight for at least a week or two after the Winter Solstice (December 21st). The total lack of UV B halts growth in plants (and most vitamin D production in humans).
We got around that hurdle last year by simply having a large enough selection of herbs that we could cut one and then not have to cut it again for at least a month or two. That allowed each herb to slowly grow back to harvest readiness.
In future articles, we will discuss artificially replacing the missing UV spectrum with grow lights of different types.
As a side note, while editing this article I walked outside to see this!
So I gotta go take care of that. I’ll let you know how it turned out next time!