Building Your Own Garden Greenhouse

Many do-it-yourselfers find building a greenhouse to be a fun and rewarding project. While many gardeners build a greenhouse successfully, over the years, we have also witnessed other do-it-yourself greenhouse building projects that would have benefited from better planning before they started building a greenhouse. Before beginning construction, you should do plenty of research on how to build a greenhouse. Be sure to speak with other greenhouse gardeners to get their input and suggestions, but also consult many of the relevant greenhouse construction and planning books available. You need to consider your regional climate, the best location to build a greenhouse, as well as the greenhouse constrution materials and the general greenhouse design you want.

When building a greenhouse, you need to ensure that the greenhouse you construct will be adequate for your region. For example, if you often get heavy snow you need to use materials that are especially strong and durable when building a greenhouse. You may also choose to include center supports to help brace the greenhouse structure. Another concern with cold weather is heat loss. If you plan to use the greenhouse year-round it will be important to choose insulated framing and insulated greenhouse covering materials that will help hold in the heat. Many people must also deal with the challenges of windy areas when building a greenhouse. In this case, it is important to choose sturdy greenhouse building materials and design your greenhouse with a shape that will allow wind to pass over the structure. (Rounded styles often work well for high-wind areas.) When finished building a greenhouse, you will also want to secure your greenhouse to the ground or a foundation to ensure it will not blow away.

One common mistake when building a greenhouse involves preparing the site prior to having the exact specifications of the structure. As a general rule, you should never prepare a foundation prior to purchasing your greenhouse. Many people find that they are not able to find a greenhouse that fits their foundation size, or that the greenhouse differs slightly from what they had planned for when constructed. From our many years of experience, we actually recommend that you do not lay a formal foundation for your greenhouse. It is much better to simply level the ground and then place pea gravel or flooring material where you want to put the greenhouse. This allows for much better drainage, which helps to keep the greenhouse clean and disease-free. It also makes it possible to easily move the greenhouse if necessary and is much less expensive.

The location for your new greenhouse should also be chosen with care before you begin building your greenhouse. It will need plenty of sun, although some partial shade may be fine. Southern exposure is best. Orient your greenhouse so it gets as much Southern exposure as possible (exp. if you have an 8'W x 16'L greenhouse, the greenhouse should be oriented East/West so the longest side faces south.) Make sure that you will be able to run electricity and water to the greenhouse if you so desire. Many people building a greenhouse also make the easy mistake of assembling the structure in another location and then when they go to move it realize that there are fences or trees in their path.

Today there are more options for greenhouse materials available than ever before. Popular framing choices include wood, aluminum, steel, PVC, composite or resin. As far as covering materials go, you can choose from polyfilm, glass, high-density polyethylene (such as Solexx greenhouse covering), or polycarbonate. Each has distinct drawbacks and benefits, so it is best to thoroughly research your choices. Read more about greenhouse frames and greenhouse covering materials.

In order to ensure that you build a greenhouse that is as functional as possible, you need a detailed and well-designed plan. When building a greenhouse, you should provide supports for the greenhouse covering material approximately every two feet. The greenhouse covering can be built into the frame via channels, or it may be applied with screws in some cases. If this is the case, plan on using approximately one screw per square foot. As you consider how you will apply the covering material, also plan for vents. You will need at least one large vent to allow proper air flow, but you should also add base vents and fans for optimal ventilation. Read more about ventilation.

One advantage of building a greenhouse yourself is that you can configure the inside to best fit your growing needs. Left over greenhouse framing material can be used to create a basic bench frame structure for the shelving. It is best that you use shelving made with some kind of wire instead of a solid material. This allows for better drainage and also permits necessary fresh air to flow to the roots of your greenhouse plants. Be sure to use a strong shevling material (often times people will use rabbit hutch covering or something similar, for example) and plan for plenty of room for both small and tall plants. For extra space, it may be possible to add hanging rods if your greenhouse building material is strong enough.

With all of this said, it is important to make one more important note about building a greenhouse. While it works out well for some people, especially those with specific requirements, this ambitious endeavor does not always have the best results and is often more costly than simply purchasing a greenhouse kit. After considering the cost of the materials when purchased individually as well as extra materials for errors, you may actually spend less money and be more satisfied purchasing a greenhouse kit than building a greenhouse yourself. Even if you think that you will still end up building a greenhouse, we highly recommend looking into the greenhouse kits available. You may be surprised to find one that will work well for you and, if nothing else, these greenhouse kits will give you further ideas about building a greenhouse of your own.