Climate
If you have been gardening for awhile already, you have discovered how expensive it can be to buy all the starter plants that you need to get your garden started. At least here in the Midwest, there are several garden plants (tomatoes, peppers, melons, etc) that would never realize their full potential if they were only seeded directly in the garden. To ensure that you maximize the productivity of your garden, and minimize your expenses, having a small backyard greenhouse is a great way to put you one step closer to self-sufficiency. However, if you live in a southern or coastal state, you may not need a greenhouse because of the long growing season.
Materials
When it comes to deciding what style of greenhouse is best for you, maybe a few thoughts from our experience might be helpful. A fast, easy, and cheap greenhouse that is made of a plastic canopy might last a few years before the sun degrades the plastic and makes it brittle. The wind making the plastic sheets ripple constantly will also weaken it. Then when there are high winds or a hailstorm, you will have a big mess to clean up and possibly a loss of your plants. The periodic replacement cost of the canopy of this type of greenhouse will be an inevitability. With all those problems, we suggest investing your time in a greenhouse made from used tempered glass window panels such as “failed” patio doors. There will always be used windows available if you are willing to look. A couple good ways of locating enough free glass for your project would be to contact your local window & glass repair shop, and by placing an ad in the local paper that you are looking for old patio doors (people remodeling their houses are usually willing to give you the glass instead of paying the trash man to haul it away). Houses are often being remodeled and having windows replaced, and insulated tempered patio glass panels sometimes “fail” and lose their insulating qualities. Unless you plan to have a heated greenhouse to grow plants year round, building your greenhouse with functionally insulated glass is not necessary because the average self-sufficient gardener will only need the greenhouse for a couple months in the Spring.
Size
For the average self-sufficient gardener feeding just one household, a greenhouse with dimensions of 16ft x16ft will provide plenty of space to get all of your garden plants started. For a 16ftx16ft greenhouse you will need approximately 15 or more glass panels from average sized patio panels. We stress that the glass be tempered glass because it is much stronger and safer if a panel breaks. Our greenhouse has survived two severe storms with hailstones larger than golf balls and not even one of the panels cracked. If it was a cheap poly greenhouse we would have had to replace the canopy twice in one month, not to mention all of our plants. Our experience with poly greenhouses has been that the wind would often rip the canopy off as well. That being said, it is a good idea to put your efforts into something that will last for your whole gardening career and be much less expensive.
Materials
Once you have all your glass, it is time to design the frame of the greenhouse. Because patio glass panels will vary in size, wait until you have enough glass accumulated before you build the frame. Approximately $700 worth of treated lumber will be enough to complete the project. Be sure to use entirely treated lumber or other materials that can withstand constantly wet conditions, as you will want to be able to spray a lot of water. Also, be sure to have a vent that you can open near the peak of the roof to vent the excess heat when necessary. Because the size glass that you can get your hands on will vary, we don’t provide plans here for the structural designs. If you or a friend have a bit of carpentry experience, you can have your new greenhouse up in a weekend or two. If you do not have much experience with handling large glass panels, just remember to keep the glass from resting on any exposed nails, screws, staples, or other metal, as this will likely cause the glass to crack. Only allow the glass to rest on the wood frame or maybe rubber shims. As long as your framing is strong enough to support the weight of the glass, there is no wrong way to build your greenhouse.
If you would like further assistance with the specifics of what would suit your needs, please use our contact form to request a free consultation. We will be happy to help you with the design of your new greenhouse. We also provide free video tutorials on our Youtube channel to help you reduce your cost of living.