Build a greenhouse to grow during winter

Now that we have experienced cool night temperatures the hardy mums have finally advanced from bud stage into flower and are creating beautiful displays of fall color. This is a great time to plant hardy mums to enjoy now; pansies, ornamental kale and cabbage to enjoy most all winter; as well as trees and shrubs for the long term.

It is also the season when many folks decide to build or add a hobby greenhouse to their yard to overwinter their tropical’s and container gardens or to continue the joy of gardening through the wintertime and to get an early start on spring.

There are many choices when you decide to add a greenhouse. You can build your own metal or wood frame and cover with a greenhouse glazing or you can buy a greenhouse kit ready to assemble. You can install a freestanding greenhouse in your yard or add a “lean to” off your home or garage.

First decide how you plan to use the greenhouse and that will answer many of the questions about location, glazing, heating, ventilation, light levels, benches and controls. Your needs will be different if you are overwintering large container plants, growing greenhouse tomatoes, orchids or “cool” crops like leaf lettuce or perennials.

If you are growing a “warm blooded” crop like greenhouse tomatoes, tropical’s or orchids you will want to use a more energy efficient “skin” or glazing for the greenhouse like insulated glass, twinwall acrylic or the most popular choice these days is twinwall polycarbonate panels. Twinwall panels will reduce your heating costs by 30 to 40%. The greenhouse grades of polycarbonate panels have a 10 year warranty and the acrylic panels have up to a 30 year warranty.

You also could use greenhouse copolymer or plastic films, like you see on many commercial greenhouses and they come in 1 and 4 year grades. They can be very energy efficient if installed as 2 layers with a small “pillow” of air blown between them. These greenhouse grade glazings are designed to stay clear and transmit maximum amounts of light for healthy plants.

In Oklahoma we get heat buildup in greenhouses, since they are literally a solar collector, even on many winter days so you will need to plan on how to ventilate the greenhouse space using roof vents, side or endwall vents or motorized shutters and exhaust fans. If you want to use the greenhouse in the summertime you may want to add shadecloth and actually cool the greenhouse with an evaporative cooler or a pad and fan cooling system.

You can capture heat in water or stone storage but unless you are growing a crop that can tolerate freezing you will need a heat source. Unit or space heaters are usually the best choice. Natural gas is the most economical fuel source, followed by propane and electric heat is the cheapest to install but the most expensive to operate.

Depending on the type of frame, glazing, heating, cooling, floor and bench choices you will find hobby greenhouses from under $1,000.00 to over $50,000.00. Please feel free to email additional questions and we will try to help you discover the joys of greenhousing!


One response to this post.

  1. There’s definately a lot to learn about this issue. I love all the points you’ve


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