Framing for a small--and portable--backyard greenhouse
I'm an advocate for a sustainable communities idea that is summarized by the slogan Food Not Lawns. You can click on the link provided here for a detailed description of what that means, but briefly, it is about turning as much land as possible into food production.
This isn't a new idea. During World War II Americans on the home front planted victory gardens all over the place and, during Shakespeare's time, every English village had a common green where people grazed livestock and raised apples in community orchards. Today, people in Asia and Africa routinely plant vegetables and fruit trees in every available space. I remember, for example, being surprised and delighted to see stalks of corn growing in the spaces between sidewalks and roadside gutters.
Because we want to practice what we preach, my wife and I have tried to turn as much of our Berryville lawn into vegetable gardens as possible. Our yard is mainly shady due to an abundance of large and mature trees--which we are very glad to have--and we have limited sunny spaces necessary for decent production. We cope with the lack of sun burnished dirt by maximizing every spot where it does shine. Our latest sun catching project is a mini-greenhouse that fits nicely into a narrow strip of sunshine on our back patio.
The picture above shows the framing for an 80"x30"x40" greenhouse that is ready to be wrapped in clear plastic. The completed greenhouse weighs about 90 lbs and is easily tilted upright for watering plants or cooling them on warm days. Many people like the idea of having a backyard greenhouse to start garden seedlings, but lack the space to make the idea practical. One solution is to scale everything down and "get small." The greenhouse shown here is made entirely from recycled and found materials and cost less than $10 to build, including plastic wrap. Here are the parts you'll need:
4 80" 2x4s
4 30" 2x4s
3 30" 2x10s
10 26" 2x4s
2 38" 2x2s
1 sheet of 2 or 3 mil plastic wrap 10' x 12'
Assorted drywall screws
Cut the ends of the 80" and 30" 2x4s at 45 degree angles and attach them like you are making picture frames. You'll have a top and bottom frame. Take 8 of the 26" 2x4s and make 4 corners by screwing them into posts. Attach the top and bottom frames to the corner posts with 2.5" screws; take the two remaining 26" 2x4s left and screw them into the frames at the midpoint between the posts.
Gable ends are made by cutting the 3 2x10s into triangles to provide your greenhouse with a "pitched" roof. I scored lines from the midpoint of the 2x10 (the 15" mark) to points about 2" from the bottom of the left and right corners. Secure the 3 cut 2x10s to each end and in the center of the top frame with 2.5" drywall screws. Finally, screw the 2x2s between the gable ends and the center piece to make the building's ridgepole.
The picture above provides good general guidance but, as always, feel free to change the sizes and dimensions described here to fit the needs of your space. It took me about 3 hours to make the greenhouse described here. That included time for two cups of coffee and plenty of advice from my gardening partner. Good luck with your greenhouse!