Certain plants in the greenhouse, such as the tomatoes, are getting to a size that soon they will need to be transplanted into larger pots. That means I have to make room in the greenhouse and move more cool-weather tolerant plants outside. We are still having nights where the temperature dips to the upper 30sF, which is a little too cool for continued good plant growth, and encourages diseases that can hurt the young sprouts. So, today I built a little hoophouse, a miniature greenhouse, for some of the plants. I thought I'd share the process as this is a simple project that anyone can do for their plant starts as they wait for the weather to warm enough for planting in the garden.
In order to keep the grass at bay, I laid two pieces of ground cloth side-by-side with a little overlap and secured them to the ground with ground staples. This strip is about 4-feet wide and 42-feet long.
A few of the ground staples. Note the rust. They've been used many times and will probably rust through in the next year or two of use. As it is, the metal is not very strong, and a sub-surface rock will bend them, stress the metal, and render them useless.
If you enlarge this picture, you will see small pieces of 3/8" rebar sticking out of the ground in the left foreground. They will anchor the 10' lengths of 1" PVC that form the frame. The rebar is about 12" long, and I drive it into the ground about 6", provided I don't hit rocks. I hit a lot of rocks, probably buried gravel, toward the back of the picture. It figures.
Other 10' lengths of 1" PVC are connected together to create a top support for the hoops. I used 2- 1/2" drywall screws to connect the top support to the hoops. (Shorter ones will do just fine. I used what I had laying around.) I next tied a length of heavy twine to the ends of the frame where the top support and hoop meet, stetched it down to the ground, tied a piece of rebar to the loose end and staked it into the ground. This provides additional rigidity to the frame.
It's a lot easier putting the plants in the hoophouse before the covering is put on. A final hit with the water hose and...
Trying to put plastic on the frame in a 10 mph variable wind can prove to be a bit trying, yet I eventually got the job done. The plastic is 10' wide (very convenient since the PVC is 10' long), and is 6mm thick, which is perfect for this project, primarily because it won't break down from the UV light as quick as thinner plastic, so I can reuse it in the furture. A couple final touches and the hoophouse is complete. Note that I bunched and tied the plastic on the end and staked it down. Also, there are plastic clips at the base of each hoop. They are designed specifically to secure the plastic to the frame and can be purchased through a couple different gardening catalogs. This picture was taken before I placed additional clips about 3' up on each hoop to help make the platic more secure in heavier winds. (Rest assured, the wind will occasionally have its way with this structure.)
Believe me, it will get plenty warm in this little structure. So much so that I will have to lift up the sides during the midday sun. The clips come in handy at this point, for when I lift up the plastic, I can clip it down to the upper part of the frame so it doesn't blow around. And one final note: if you lift up the plastic on one side, you have to do it on the other side as well. Otherwise you might find that you have instead constructed on really big kite.