Running A Greenhouse Aquaponics System All Winter

Hey Trifecta fans.

As we head into the cold months of winter, we’ve been receiving a lot of questions about how we are able to grow throughout the winter here in New England, especially without heating our greenhouses. Part of the reason is with aquaponics we get an extension on the growing season from our plants. However, simply putting your aquaponics in a greenhouse is not going to be enough to 100% year round growth.

Snow collapsed greenhouse still runs
Due to the harsh nature of New England winters, we have had to adapt and implement a variety of different tricks and strategies to ensure that we are able to get year round growth. This post will focus on one of the easiest and cheapest strategies that we use that can be adopted into any garden, aquaponic or otherwise: the implementation of what we call “mini-greenhouses” within your greenhouse.

Our current greenhouse at Robb’s Farm is a 30×34 and has an apex of over 15 feet. However, within this greenhouse our trough beds currently full of lettuce varieties are only a foot off the ground. This leaves a lot of unused overhead airspace, airspace that while warmer than outside is still colder than our water, costing us added electricity to maintain our 55-60 degree water temps. What we have done to mitigate this heat loss is create a heat trap over each trough by building a PVC frame to drape clear plastic sheeting over each trough. This PVC frame holds the plastic sheeting about a foot above our lettuce heads.

The installation of this “mini-greenhouse” has many benefits. First and foremost, it creates a solar effect during the day creating a lot of heat within each mini greenhouse. This gives the plants a better daytime environment. It also heats our water during the day, saving us on electricity needs.

The real magic, however, comes after the sun goes down. We have a lot of water running through this system. This water acts a big heat sink. This is because it heats up during the day and then slowly releasing that heat at night. By trapping that releasing heat within our “mini-greenhouses” this heat does not recede to the top level of our greenhouse where we have no plants. Instead it is directly benefiting the plants ensuring that they never have to endure a frost point. In addition we trap the condensation within the mini greenhouse that normally collects on our main greenhouse plastic.

This water falls back into the trough, rather than being lost from the system. This improves not only our water conservation but also the vitality of our system. Any time you have to add water to your system to make up for loss, it dilutes the beneficial bacteria in the little ecosystem you have created. The less water you have to add, the stronger you allow your system to grow. This is especially true in the early stages of system development.

“Mini-greenhouses” are not a new technique to gardening, but they are relatively new in the world of aquaponics. Traditionally, aquaponics practitioners are from more tropical climates, such as Hawaii or the Virgin Islands. So bringing it to New England brings additional challenges.

The “mini-greenhouses” are one of the better strategies we use to alleviate the challenging New England winters. They allow us to maintain a healthy and productive system year round. Check out pictures below of the construction process. Please make sure and stay tuned for my next post which will include how you can plan and build your own mini greenhouses for your home garden , raised beds, or greenhouse.

The Trifecta team.

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