Heating Your Greenhouse
Winter is fast approaching and many of you are thinking of heating your home greenhouse over the winter months. There are few things that one must consider when growing into the shoulder season and into the cold winter months. One must consider: the amount of heat needed (BTU), source of heat, ventilation, lighting, what crops to grow, irrigation and how much money you can spend to heat it.
It is possible to grow crops all season long, but you are limited by how much heat and light you can provide. It is expensive to run a greenhouse during the winter months (below 0C outside). A greenhouse isn’t very well insulated and will cost money to heat.
1) Which Plants Are You Going to Grow
When determining if and how warm you need to keep your greenhouse, you must first decide what crop(s) you are going to grow. Cool-season crops can be grown at lower nighttime temperatures than warm-season crops and so on. Cool-season crops also require less light. When growing cool-season crops, one can get away without heating, however, if growing warm-season crops and houseplants, a heat source and lights are required. You would be surprised on how much heat (BTU) and the cost.
To learn more about plant choose, join our workshop on October 8, 2022. See our Facebook page for more details.
2) Temperature
Have you decided what you are going to grow? Now you can calculate the amount of heat or BTU you will need (this will help you size your heater). From there you can calculate the cost. Join our workshop on October 8, 2022 to learn how to do these calculations. See our Facebook page for more details.
Sources of heat include electric heaters, space heaters, propane and natural gas heaters, and wood or pellet stoves. Keep in mind that many of these heaters will need to be ventilated to the outside. During our workshop we will introduce you to these methods of heating and also more sustainable and cheaper options.
3) Increase the Efficiency
Greenhouse cover materials like plastic and glass are poor insulators and let all the heat out. Therefore, in an unheated greenhouse the nighttime temperature inside the greenhouse will be about the same as outside temperatures. In Canada, greenhouses need to have some type of heat source to keep most plants alive and growing.
There are many ways to increase the efficiency. This includes root zone heating, tents, and choosing the correct cover material (polycarbonate etc.). Join our workshop on October 8, 2022 to learn more about how to do these calculations. See our Facebook page for more details.
4) Other Considerations
Light, ventilation, and irrigation are other considerations that we will go into more depth on our Heating Your Greenhouse Workshop.
Please email us or message us to sign up for our next workshop - October 8, 2022 at 1 pm.