Where to put your greenhouse
Patrick Boyle
Greenhouses can provide an extended growing season, amplified sunlight and heat, and a controlled environment in which to grow plants.
If you're planning on building a greenhouse, location is the most important step in its creation. Deciding where to locate your greenhouse is a critical planning step. Unless it's portable, the greenhouse is there to stay.
The most important consideration in deciding on a location is sunlight. Your greenhouse should get at least six hours of direct sunlight a day. Study the path that the sun takes and take note of any shadows that may fall on the greenhouse. Obvious obstructions to the sun include nearby buildings and trees, and farther away, high-rises and hills. Remember that the sun follows different paths across the sky in the summer than in the winter.
Early morning heat from the sun helps protect the plants against freezing and recharges the heat-storage system sooner in the day. Plants also grow better when they get early morning sun light.
The orientation of the greenhouse is also important. An east - west greenhouse will allow in more light than one that is situated north - south.
Drainage is another important consideration in selecting a site for your greenhouse. Don't put it in dip that will catch rain and snow. Also avoid boggy areas where soil is constantly wet. Climate control will be much easier if the floor of the greenhouse is relatively dry.
Keep in mind that access to water and electricity is another important factor in locating your greenhouse. The farther the greenhouse is from these connections, the harder and more expensive it is to run water and electrical lines there.
Locate your greenhouse so that it takes advantage of available windbreaks. Windbreaks can reduce heat loss in the winter. Near by buildings or trees to the west and north of your greenhouse act as windbreaks to slow the winter wind before it hits the greenhouse.
Here are some other links that you might find helpful -
www.ag.usask.ca/cofa/departments/hort/hortingo/misc/greenhou.html
www.pond.com/~johno/greenhouse.html
Adapted from Easy Living Gardening 1997.