We’ve been talking about a greenhouse since we bought our house. We both would love one, but we still have a number of projects higher up the list than a greenhouse (the barn roof, bathroom remodel, refinishing wood floors, the intermittently leaking chimney, etc.). Still, the idea of extending the growing season is just too good to pass up, and our small raised bed pvc hoops have been so great we decided to try a pvc hoophouse (HH) made from conduit. We purchased the materials and got started earlier this month, and Tuesday began construction in earnest. Here’s the process.
We have serious groundhog issues, so the HH would need to be within the garden fence. We decided to increase the fenced area slightly on the eastern side of the garden, and sited the HH in the northeast corner of the garden, against the north side fence, to the east of the raised beds, running in a N-S direction.
Our site had previously been worked as a garden bed, and last winter held the hen’s snow dome, so it is level (mostly), and a well drained as any spot in the garden. We held off planting there knowing the HH would be sited there, but finally had to break down and plant our second crop of tomatoes, started especially for the HH, before we’d built it. We only damaged one. But before we could begin, we had to pull up the volunteer pumpkin/squash plants growing there. Oh! The carnage! There was fruit already!
Next, we used large deck screws to construct the2″X’6′ base. Prior to putting the base together, we had measured the location of each rib and screwed conduit clamps in place for holding the hoops in position. The finished size of the base is 8’x16′. One the (southern) door entrance end, we put the 2″x6″ with the 6″ side to the ground to make a sill and provide a nice base for the end wall frame. Note the tomatoes on the right, contrasting with the cardboard under the base on the right in the photo (as weed prevention). Later, we’ll cover the cardboard with mulch.
Once the base was completed, it was time to set up the hoops. Because we occasionally get heavy wet snow or big storms with over 16″ of snow, we decided to place the hoops fairly close together. The hoops are relatively inexpensive components compared to the cost of constructing a new HH should this one collapse under snow. We originally planned for 7 ribs, but ended up with 8 ribs at approximately 21″ intervals. We still need to pick up 4 additional pieces of conduit to complete the rib installation.
We wanted the final height to be between 6 1/2′ and 7′ in height, so we set it up and determined we needed to remove 1′ from each conduit –in essence the HH is now constructed from 2-9′ pieces of conduit attached in the center. If we had been able to make the HH a little wider, we would not have needed to trim the conduit, but we just didn’t have the space. If this experiment proves wildly successful, we will probably make space in the future for a wider and probably longer HH.
Once we were certain we liked the height, we tightened the screws holding the conduit in place, making sure the conduit was level with the bottom edge of the baseboard.
We found 16′ lengths of 1″x3″ at the lumber store, so we decided to use that for purlins. We attached the side purlins 36″ from the bottom of the baseboard, using 2 self-drilling screws for each rib to minimize torquing. Be sure to pre-drill holes at the ends of the 1″x3″ to prevent splitting. We installed both side purlins and called it a day. We’ll attach the center purlin next, and add the final 2 hoops. Note the tight spacing between the new hoop house and the raised bed with shade cloth on the left. I need to get cardboard for weed control down on that side, too.
We need to order greenhouse plastic, and later in the season we will put the cover on. I think we will order wiggle wire to attach the plastic at the side purlins, which will allow us to easily roll up the sides to vent the HH in the summer. We also need to frame in the southern end and attach a door. We have a big pile of door possibilities in the barn attic, as well as lots of scrap for this part of the project. Before this we will work on prepping the planting beds in the HH and planting our first crops.