Greenhouses vs. Row Cover vs. Innovative Garden Design
The allure of having a greenhouse in a cold climate is very strong for gardeners, both new and experienced. Greenhouses can be an excellent season extension tool; however, they come with some problems too! They can be a great resource for season extension (growing crops earlier in the spring and later in the fall) as well as creating an environment that provides a little extra boost for heat loving plants such as peppers and melons. However, a greenhouse can become a fiery oven in August and requires some thought in regards to ventilation and air circulation to prevent overheating, excess humidity, and molds. Even in the Elk Valley, greenhouses often require shade cover during periods of extreme heat. Greenhouses can be expensive too!
Greenhouses utilizing plastics need to be replaced every five to 10 years depending on the material used. Heated greenhouses consume a massive amount of energy, and even passive solar greenhouse may require electric fans or daily manual interference (such as opening and closing windows). The windows on my greenhouses have a gas spring. As soon as the greenhouse reaches 15 degrees Celsius, they automatically open! It’s just one less thing for me to remember so I can focus on my baby chicks instead.
There are also some amazing and innovative people out there trying to solve these issues related to passive greenhouse in northern climates. Paul Wheaton has created a ‘truly passive solar greenhouse’ that requires zero electricity and is designed to be a year-round greenhouse in Montana! Check it out on YouTube.
Row cover can also be used for season extension to protect from hard forests, reduces insect damage without harmful chemicals, provides hail protection, and can shade plants during the heat of summer. Row cover is usually a semi-transparent fabric spread over hoops to protect crops. Unfortunately, row cover still has its downsides: it is usually made of plastics so you risk introducing micro plastics in the soil, it is easily torn, and requires regular maintenance and manipulation. There are cotton alternatives, but they are hard to find. I find row cover so effective in reducing insect damage for crops such as spinach, broccoli, cauliflower, Bok choy, and baby greens that I find it well worth my time, money, and effort to maintain.
Thoughtful, innovative, and creative garden design can resolve a lot of the issues faced when growing food in a cold climate and can mitigate the need for expensive and petroleum based alternatives. The need for a greenhouse or row cover can often be mitigated by selecting different cold hardy crops, ‘living row cover,’ and creating different microclimates through alternative garden bed design and earthworks. Garden design is a big nut to crack, but I will delve into microclimates more next month!