If you love gardening and wish there was a way to start your plants earlier, then building a greenhouse is a great solution. These instructions tell you how to build a small, backyard greenhouse that's perfect for starting spring veggies and flowers. Made with sturdy cedar fencing and steel mesh, it measures about 6 feet long by 4 feet tall and is durable enough to last for years. The tunnel-like shape makes it attractive and easy to access.
- 6 2x8-inch cedar planks, cut to 6 feet in length
- 8 6-foot cedar fence posts
- 3 16-foot lengths of steel mesh ( 2 feet wide)
- One piece of polyethylene film, measuring 6 feet by 16 feet
- Two pieces of polyethylene film, measuring 4 feet by 6 feet
- 20 sturdy clips
- A post digger
- A hammer
- Thin, flexible wire
- A tape measure
If you're having trouble finding cedar planks or posts, contact a local fencing company and ask if they will sell you some of these materials. It is important to use cedar, since it is resistant to decay and insects. Other woods would have to be treated with sealers or insect repellents to prevent breakdown and infestations, which would not be ideal if you're growing edible plants in your greenhouse.
Step 1: Laying the floor.
The floor of this greenhouse will be made from the cedar planks. It will sit flat on the ground and make it easier to slide plants in and out of the greenhouse than if you were to have a plain dirt floor. Lay the six cedar planks next to one another so that the ends line up and you have a 4-foot by 6-foot rectangle. There's no need to attach the boards together. They'll stay in place under the framework of the greenhouse.
Step 2: Placing the posts.
Along both of the long sides of the floor, measure off and make a chalk mark every 2 feet. You should have a total of 8 marks -- 4 on each side. At each of these marks, dig a hole using your post digger. You may have to temporarily move the floor boards and then put them back in place later. Then, insert a cedar fence post into each of the holes, and use the hammer to pound it into the ground until only 4 feet of the post is above ground level.
Step 3: Configuring the steel mesh.
Take one piece of the steel mesh. Line one end of it up with the bottom of two of the fence posts that are 2 feet apart from one another on a long side of the floor. Use pieces of your thin, flexible wire to secure the mesh around the fence posts. Twist the wire tightly so that the mesh does not move. Continue up the fence posts, securing the mesh along the way. Then, pass the mesh across the space that's occupied by the floor boards to the other set of fence posts located directly across from the pair you've been working with. Use more strips of wire to secure the mesh to these fence posts, continuing until you reach the bottom of the posts.
Repeat this process 2 more times until you have steel mesh attached between all of the fence posts. You should now have a tunnel-shaped structure that measures 6 feet long by 4 feet wide.
Step 4: Clipping on the polyethylene sheets.
You may need a buddy to help you with this part. Stretch the large polyethylene sheet over the greenhouse, and secure it to the ends of the steel mesh with the clips. Then, hang one of the smaller polyethylene sheets at the front of the greenhouse, and the other at the back, using the clips to attach it to the steel mesh.
Step back and admire your work! You can push the front and back sheets to the side to put plants into the greenhouse. When winter comes, you can remove the polyethylene sheets from the steel frame so they don't get ruined, and replace them the next spring when you're ready to use the greenhouse again. For additional reading on cedar fencing for your greenhouse, follow the link in this sentence.