The Challenges

  • More Heat: A place to help plants that love more heat i.e. peppers, tomatoes, okra. Montana can have some cool summers. A greenhouse will help keep plants a bit warmer in the cooler summers.
  • Climate Change: A buffer from climate change. Temperatures have been variable in the spring and fall. Late frosts in the spring, early in the fall.
  • Deer: An easy way to keep deer out of the plants
  • Longevity: A greenhouse that will still be an asset in several years.
  • Structure Challenges: The neighbors put up the same cattle panel shed in two different configurations in the last year. Both had epic fails. One setup blew into our upper field and the other collapsed during a mild wind event. Another greenhouse in our neighborhood (I do not know what kind) collapsed from the snow load last year – and we did not have that much snow. In addition to these issues, there is the issue of height.
  • Height Challenges: The arch of the cattle panel defines the height and the pitch of the sides for shedding snow. A width of 10 feet results in a height of 5′ 5″. Just barely tall enough for me. It would be nice if the taller members of our family could walk upright in the cattle panel hoop house.
  • Environmental Considerations: Our final consideration is to use recycled materials when possible and of course be as easy on the budget as possible.

Now that I know what we want and some of the issues to avoid it was time to start reading, watching YouTube videos and searching the web. I learned:

  • Raising the whole setup off the ground by a foot will add the head room needed and make ventilation easier. 10 feet wide would give a height of 5.63′, adding a foot of height – 6.63. Plenty tall enough for this family.
  • PVC tubing reacts to plastic sheeting (due to the PVC off gassing) – reducing the life span of the sheeting. So I cannot use that to hold down the plastic on the north and south sides.
  • Different bracing techniques. We may want to be able to have a shelf for starting more plants. Keeping the supports the same height will allow us that option.
  • Adding rope or bailing twine over the plastic sheeting will help stop the wind damage – Gardening with Leon
  • Removing the plastic sheeting in the summer can extend the life of the sheeting. From 4 to 7 years – Gardening with Leon
  • I was surprised that very few websites or videos mentioned wind and their cattle panel greenhouse. We live in Montana (zone 5) – and the wind sure can blow here. We are not in town where there are fences and houses to slow the wind down.
Arch Graph for Cattle Panels
Arch Graph for Cattle Panels

Construction

The current garden beds are 17 feet long. We decided to go with 4 – 50″ x 16′ cattle panels which would cover 3 existing rows of our garden. 200 inches or 16′ 6 inches long and 10 feet wide. Our cattle panel greenhouse will be raised and supported by 18 cinder blocks and angle iron. It will run east and west. The longer north/south walls will each have 4 cinder block supports. There will be four cinder block supports in the middle of the greenhouse to help with snow load.

Our wonderful cement mixer made this chore a breeze. Thank you Bill Bogart for the cement mixer! It took us a few hours to set up and pour the concrete. We used one 80lb bag of mortar and gravel we had on hand. They took two days to thoroughly dry.

Cinder Foundation Blocks Note: If I had to do it over again I would put the post in the middle instead of on one end of the cinder block. Then the angle of the angle iron could be changed easily. And bedframes can be very hard to drill into. We were lucky, we only had to drill a few holes.

We used angle iron from old bed frames. Each leg of the frame is in the cinder block to stop the wind from pulling the angle iron out.

Karl leveling the cinder blocks.
Karl leveling cinder blocks.

The cinder blocks are set deep enough so we can plant above the blocks. It is easy to see the garden soil we have worked hard to build.

It took us 3 days to set the posts, we had a few distractions. I decided to add about 8 inches of compost from our compost pile. It is much easier to add with the backhoe now than wheel it all in later.

We used 8′ 2×6 along the north and south sides to hold our cattle panels up. We added the east and west walls. Our expectation is that the west wall will have the most stress. North, south and east all have at least some buffer. Not the west. We added Solexx in the center panel and plastic that will be easy to replace if it tears. We had just enough left from our pit greenhouse to do the west side and part of the door on the east side.

Finished Cattle Panel Greenhouse
Finished Cattle Panel Greenhouse

This is how the greenhouse will look during the summer months – with a shade cloth. The wiggle wire is in place to make adding/removing the plastic covering easy.

Cutting the pipe insulation every 8" to cover the cattle panel joints
Cutting the pipe insulation every 8″ to cover the cattle panel joints

We added the plastic covering this fall – the last warm windless day in November 2021. It is my understanding that the plastic is best added when it is at least 60 degrees. We made sure the greenhouse was reasonably air tight and ready for the storm coming in the next day – with high winds. Oops, I almost forgot! We added pipe insulation over the cattle panel seams. The goal is to buffer the plastic from the tie wire we used to connect the panels. The wires were 8″ apart. Using a small saw we cut the pipe insulation 50% through. It will be easy to remove in the summer with the plastic.

In addition to the wiggle wire holding the plastic in place we added bailing twine criss crossed across the top of the greenhouse. The goal with the bailing twine is to hold the plastic in place – to stop the rippling from the wind. Once the rippling starts – then the plastic tears easier. It worked. The plastic was in place with no damage at all.

Inside the Hoop House

Inside the Cattle Panel Greenhouse

My original plan was to have three rows inside the greenhouse. By creating the snow support I limited myself to where the rows can be. I do not want to waste precious dirt, so I removed the top soil I had added in the isle. I moved it to the sides. I now have about 10 inches of beautiful, rich soil.

Life is starting to show in the greenhouse – and I really do not want to be pulling weeds in the winter. Tomorrow I will lay down some newspaper to keep weeds down.

Next steps:

  • Add sensors to monitor soil temps and air and humidity temps.
  • Create a webpage so I can monitor from anywhere
  • Create the center path