Building a hoophouse

On Monday and Tuesday SJC hosted a workshop on how to build a high-tunnel greenhouse, also known as a hoophouse. The purpose of a hoophouse is to extend the growing season for vegetables, allowing harvesting to continue later in the fall and to begin earlier in the spring. This venture was funded by a Ball Brothers Fund grant of $25,000 to the college.

When I arrived at the site west of the campus, there were a lot of pipes laying on the ground.

 There were more than a dozen people there, many from two of the co-sponsoring agencies, Jasper County Soil and Water Conservation District and the Natural Resources Conservation Service (NRCS) of Jasper and Newton Counties. I tried to stay out of the way of the people who knew what they were doing and looked for something with which I might be able to help.

Eventually I ended up helping build the hoops. They were assembled from smaller pieces, then the bracing was added. Each of the hoops had about twenty bolts or metal screws holding it together, and getting everything lined up so that the bolts and screws could be put into place took time. Below two of the guys are finishing up by adding some metal screws to firmly attach the braces to the bars.

 While I was working on hoops, other people were assembling what would be the walls of the structure. The whole structure is designed to move on a track. The structure itself will be about 75 feet long, and the track will be double that. In the fall you can have the frost-sensitive plants protected while you plant frost-tolerant plants in the uncovered section. When the weather gets colder, you move the tunnel and let your frost-sensitive plants die so you can keep the frost-tolerant plants growing into the much colder weather.

 It was hot and I was afraid I would overheat, so I left early on Monday. When I arrived back on Tuesday I was surprised to see that the finished parts were being erected and the tunnel was beginning to take shape.

 I did not feel comfortable working on the ladders, and found that I was useful helping with adding a second board to the walls and then installing aluminum track along the sides. On the left of the picture below you can see two ladies finishing up the track, putting in the final screws. The track required about 300 screws, and the whole project took thousands of bolts, nuts, and screws. The people under the hoops are adding some cross bracing to make the roof more rigid.

I wanted to go to the ground breaking ceremonies at the Fair Oaks Pig Adventure, so I again left early. I checked back this morning to see if they had completed the end caps, but they had not. The expert on the project said that the task was half done when all the hoops were up, which happened around 10:00 on Tuesday. So there is still plenty of work to do, but school is starting soon and there should be a large pool of students who can volunteer to finish the construction.

The structure certainly is a lot more complex than the picture that was in the SJC press release. I do not know how well the plastic will hold up to the weather, but it will take a very strong wind to damage the skeleton that we built if that structure is properly tied down. This kind of structure would be very difficult for the casual gardener to install--there were probably close to 200 man hours invested in building this, and it was not complete. Many of the tasks required two, three, or more people to do. Building the hoops, for example, required at least three, and installing them required more than that. However, something smaller with more of the assembly completed might have be attractive to many gardeners.

This was as close to a traditional barn raising that I will probably ever see.

Because the plants are grown inside, they will need to be irrigated.

It will be fun to see what they end up growing under it. Sodexo, the food service company that runs the dining service at SJC, has agreed to purchase produce from the project.