SnowGrow 2020
Photo and text by Tyler Bogartz-Brown
Chicago gets pretty darn cold. For food producers in the city, the growing season comes to a shivering halt around late October and may not be warm enough to plant again until the following May. Buuuuuut, we could produce a heck of a lot more food if the current 6-month growing window was closer to 8 or even 12 months long.
If the cells of plants can stay above freezing, they have the potential of surviving, and the potential of feeding people. So, how can we keep plants warm through the frigid months of the year?
One method is through the construction of solar shelters (low-cost greenhouses). These structures prevent cold air from coming in contact with plants while allowing ample light to enter from the south, and be reflected from the north.
A solar shelter traps/reflects heat back onto plants, keeping them warm. These shelters can be created using materials entirely found in dumpsters, and garbage bins. Now, imagine if all the garbage you create went towards producing food? Mmmmm garbage can sure be tasty!
In the image below we can see some of the materials often thrown away, that can aid in the urban production of food; plastic containers, food package insulation, string, rods, etc.
Here’s a good foundation for a solar shelter! This raised bed faces directly south which will give us maximum solar potential.
It’s crucial to create a solid frame for our clear material to lay over. Below is an example of an “A-frame” structure made of sticks and strings found on a thrown-out set of blinds.
A sheet of aluminized mylar is added to the northern side to reflect solar energy back onto the leaves of the plants increasing plant and soil temperature. Many poorly constructed greenhouses leave the northern portion open, allowing precious heat to escape.
On goes the polyethylene sheet! This sheet will prevent moisture and heat from escaping while still allowing solar energy to pass through.
Lettuce seeds were germinated using a damp paper towel and plastic bottle.
By April, the lettuce plants were a few inches tall giving us a 2 month head start on the growing season.
