Greenhouse Basics: Part 1-Things to Think About
Every gardener dreams of owning a greenhouse at some point in his or her life. The idea of being able to garden year round, start your own plants in the spring or extend the growing season into the fall is irresistible to a gardener. But selecting the best greenhouse to meet all of your needs requires careful thought even for the most experienced gardener. There are many factors to consider. Climate, budget, size of your yard, and how the greenhouse is going to be used all play an important role in the decision. Before you get started, it is necessary to find out if you have any local regulations that will affect the placement and size of the greenhouse. These can include building permits, setback requirements and zoning restrictions. Locating underground plumbing and electrical lines may also be required. A quick phone call to the local zoning board should yield all the information you need.
The climate where you live will dictate many of the components in your greenhouse. The weather outside the greenhouse definitely affects the environment inside. In a cold climate the low temperature is the most limiting factor to greenhouse gardening therefore, an insulated covering that will retain heat better with a tighter seal may be necessary. Also, it may be wise to insulate the perimeter of the foundation to prevent the inside the greenhouse from cooling down in the winter and plan for supplemental heat. A studier framing structure with a peaked roof may be essential to accommodate heavy snow. In very warm areas of the country high heat and humidity are the most limiting factors to greenhouse success. An active ventilation system is critical since we (I include myself here because my greenhouse is in Texas) spend more of the year trying to get the heat out of the greenhouse rather than trying to keep it in. A misting system, an evaporative cooler and a shade cloth may be necessary to grow plants year round in a hot climate. In a very wet climate, a more expensive rust proof aluminum frame may be the smartest option.
Most gardeners begin their search for a greenhouse with a budget in mind. Depending on your needs there are several affordable greenhouses on the market with an entry-level model staring about $400. The cost can climb upwards into the multiple thousands of dollars for houses that are larger, better insulated, made from more expensive materials and equipped with automatic climate controls. Some greenhouses have extension kits available to increase the size of your greenhouse without the cost of starting over. Another option to stretch you dollar is to start with a kit or build one from scratch. There are many resources available on the subject of designing and building your own greenhouse. Check with your county extension office, library or bookstore. The good news is that you do not have to buy everything at once. Prioritize the features that are most important and shop accordingly.
The size of your greenhouse is often dictated by the amount of space available. To make sure you are getting enough room, consider how you plan to use the greenhouse. Will it be used year round or just seasonally? How many square feet will it take to over winter all of your tropical and potted plants? Are you allowing space for a propagation bench? Do you need to store garden equipment in it as well? Most gardeners find that they need or want a larger greenhouse than they originally thought. Consider buying one size larger than you believe you will need if space allows. Take into account height and available headroom as well as length and width especially if you are tall or plan to grow hanging baskets. Also, consider that the temperature of a larger greenhouse may be easier to regulate over time due to greater interior air volume. A smaller greenhouse has a relatively large exposed area and comparatively less interior air volume, therefore the temperature inside the greenhouse can rise and fall rapidly with the weather conditions outside.
The style of your greenhouse is a personal preference; some are more functional than architectural. Again it depends on how you want to use the space and how much money you want to spend. Invest in a style that works best for you and enjoy.
Click here for Part 2 - Major Components of a Greenhouse