A hoop house is one of my favourite ways to protect our plants from the cold and extend our growing season here in the Pacific Northwest. Admittedly, this is our first year actually building and using one, but the concept behind it has always seemed so stupidly simple and straightforward to me that I often wonder why more gardeners don’t have a hoop house or two themselves.
A hoop house is basically a cross between a greenhouse and a cold frame. Instead of a greenhouse that is typically quite large and stationary though, a hoop house is generally lighter and more portable, fitting over top of your existing outdoor garden or raised beds. And instead of small cold frames that fit over individual plants or small clusters, a hoop house is large enough to fit over your entire garden bed, sheltering all of your plants from the cold.
We already have a small unheated greenhouse that has helped us to extend our growing season here as temperatures plummeted nearly 20ºC this week. We got our first hard frost and snowfall this week just two days after Halloween when we were out Trick-Or-Treating in short sleeves. A snowfall this early in November is practically unheard of here on Vancouver Island. And while we had made pretty good progress getting our gardens and outdoor areas prepped for the descent into winter, we certainly weren’t expecting that winter would actually come so soon!
Always Be Prepared (But Better Late Than Never)
We had made plans to build a couple of hoop houses to help shelter our winter garden plants from the snow and freezing temperatures ahead of us, but we figured we had at least a couple more weeks until we really had to get it together. After all, we were out for an evening stroll just last weekend and were commenting on how it felt as warm as a late August night!
But alas, if there is one lesson I continue to learn over and over on this homestead journey, it’s that you should always be prepared for anything at any time. There really is no such thing as being over prepared or being prepared too far in advance when you’re striving to live a more self-sufficient lifestyle. You’ve gotta have your own back and protect your own livelihood, and that most certainly includes your food source!
Now, we only have a few kale and bok choy seedlings in the ground. We’re certainly not completely reliant on our own home garden as our entire food source yet, let alone on our winter garden. But even so, I don’t want to lose the plants that we do have growing to the weather here, especially if we can do anything to help it.
When the first snowfall unexpectedly hit a couple days ago, I thought about trying to dig up our seedlings and re-plant them in the greenhouse. But the ground was already frozen solid. Plus, they wouldn’t all have enough space to grow to full size in our little greenhouse. There was really only one thing I could do: Send my husband out to the garage in a snowstorm and make him build us a couple hoop houses.
Okay, I embellish a bit. I certainly didn’t make him do anything. He was quite happy to make a trip to the hardware store (where he also happens to work) and pick up some basic supplies for a couple hoop houses to fit over our raised garden beds. And he was pretty content to escape to the garage for a few hours to work undisturbed on a quick and easy building project while enjoying a couple cold beers. And it wasn’t really a snowstorm, per se. It was really just snowing.
But the point is, we knew what needed to be done, and while we spent a few minutes kicking ourselves for not having built hoop houses sooner, we figured better late than never! Even if our plants don’t make it through the winter, having the hoop houses ready to go in the spring will help us to extend our spring/summer growing season as the soil beneath them will warm up and be workable earlier in the season.
So hubby set to work.
Measure Twice, Cut Once
The first thing you need to do is measure the space that needs to be covered. In our case, we have two raised beds that need to be covered, so we decided to build two hoop houses: One to fit on top of each raised bed. We could have built one large hoop house to fit over both of them, but we decided to build hoop houses specially fitted to each raised bed that could be attached with hinges and lifted up like lids.
Of course, if you are building a hoop house to sit on the ground, it’s not necessary to attach hinges or to measure it exactly to the dimensions of your garden bed. As long as it fits over top of your garden is all that matters. So be sure to measure the space you need to cover and then decide if you need to build a frame to those exact dimensions or if you should add a couple inches to the frame to cover an in-ground garden bed. Decide on the dimensions of the area of your hoop house and write these measurements down.
You’ll also need to decide how tall you want your hoop house to be. For our raised bed hoop houses, we decided to make each one about 2.5 feet tall, but if you are making a large hoop house to go over a larger garden bed, you might want a taller one. You will build the “hoop” part of your hoop house with ½-inch PVC piping.
We bought 10-foot lengths of ½-inch PVC pipe to make our frame, but you may need to buy longer lengths if you are making a much larger structure. In most cases (unless you are building a very large hoop house), you should use ½-inch piping for its flexibility. Any thicker and it will be more difficult to bend and could break.
Once you’ve decided how tall you’d like your hoop house to be, add the width of your hoop house frame to 1.5 times the height you would like your hoop house to be to determine how long each piece of PVC pipe should be.
For example, our garden bed is 4 feet wide and we wanted our hoop house to be approximately 2.5 feet tall. So we multiplied: 2.5 x 1.5 = 3.75 + 4 feet wide = 7.75 feet in length. We rounded up and cut each length of PVC pipe to an even 8 feet long.
As for the number of PVC pipes you will need, you will need one length of PVC pipe for approximately every 2 feet of length of your hoop house. So if your hoop house is 8 feet long, you will need 4 lengths of PVC pipe. I always recommend buying a couple more just in case:)
Gather Your Supplies
You will need the following supplies (sizes and lengths will depend on the individual measurements you just took):
- Lumber (we used pre-treated 2x4s. You can use any lumber that is long enough and wide enough to support the size of your frame).
- ½-inch PVC piping
- 6 mil plastic sheeting (or other plastic sheeting made for greenhouses and hoop houses)
- Hardware (construction screws, staples, hinges*, adhesive*, Gorilla Tape*)
- Tools (saw, drill, 1-inch spade bit or hole saw, staple gun)
*Starred items are optional or supplementary.
Building Your Frame
Next, cut your lumber. We used pressure treated 2x4s, but you could use any type of wood. We chose pressure treated wood as it won’t rot in wet weather.
Cut whatever lumber you are using to the size of your garden bed (or the area dimensions you decided during the measuring phase), and screw together with construction screws.
We added corner braces (as you can see in the above photo) to keep the frame nice and rigid. This is optional, but if you do use corner braces, cut 4 short pieces of wood on a 45º angle on each end to fit into each corner and screw to your frame.
Once your base frame is assembled, use a 1-inch spade bit (or hole saw) to drill 1-inch diameter holes along the long sides of your frame directly across from one another, beginning at one end of your frame and at two-foot intervals (or approximately) until you reach the end of your frame. Drill each hole about 1 inch deep. These holes will serve as the mounting points for the PVC pipes that will make up the upper frame of the hoop house.
Fit one end of the first pipe into the first hole on one side of the frame. Carefully bend the pipe in an arch and fit the other end of the pipe into the hole directly opposite on the other side of the frame. Repeat this process with each subsequent piece of pipe until you reach the end of your frame.
Drill a pilot hole through the lumber and the pipe in the side of the frame at each hole and drive in a 1-inch screw to secure the pipe in place. Alternatively, fill the holes with adhesive before putting each pipe in place and allow time to cure before continuing.
We used a piece of 1×2 wood to make a “spine” for each of our hoop houses to keep the hoops evenly spaced and secure to prevent it from swaying. This is not necessary, but helps to reinforce your frame. If you choose to do this step, cut a thin strip of wood to the length of your hoop house and secure it to the underside of the hoops using construction screws. *Pre-drill your holes through each pipe so as not to damage them with the screws.
Covering Your Hoop House
Use 6 mil plastic sheeting to cover your hoop house. There is sheeting available that is specifically made for greenhouses and hoop houses but in our case we just used plastic vapour barrier from the building supply store.
The goal is to cover your hoop house with a single sheet of plastic. To achieve this you will need a sheet of plastic that is slightly wider than your cut PVC pipes are long and the length of your hoop house plus the height of the hoop house on each end. For example; if your hoop house is 8 feet long and 2.5 feet tall you sheet should be at least 9 feet wide by 14 feet long.
Start by laying your hoop house on its side. Centre your plastic sheet along the length of the hoop house and staple it along the bottom edge. Add extra staples on the ends to make sure it is secure. Next flip the hoop house over and stretch the plastic over the second side. Smooth out any wrinkles and staple this end like you did with the first side.
Using a utility knife cut off the excess plastic along the bottom edge. Secure the ends by pulling the sheet from the centre point and stretching it down to the centre on the end of the frame and staple in the centre of the wood frame.
Smooth out the plastic over the end and fold the corners like a present. Staple the bottom to the frame making sure to smooth out the plastic as you go.
Cut off the excess plastic on the bottom edge and repeat on the other side. Propping up the frame to a working height by putting it on its side will make finishing the ends easier rather than trying to do it on the ground.
Once All of your ends are pulled tight, folded in, stapled together and the excess plastic has been cut off, your hoop house is essentially finished and ready to go in the garden! You might want to tape down the folded ends to prevent any snow or rain from getting in and to help prevent warm air from escaping. I would recommend using Gorilla Tape to do this as it holds better than any other kind of industrial tape (yes, better than Duct Tape!)
From here you can either lift and carry your hood house to your garden and place it overtop of your garden bed (you might want an extra pair of hands to help with this). Or if you are planning to add hinges for a raised bed, do so now and then screw into the wooden frame of your raised bed. This is how our finished hoop houses looked once we screwed the hinges into the raised beds.
And there you have it! You can keep your hoop house(s) closed and your garden beds covered during the winter to help shelter plants from snow and extreme cold, and in the spring to help warm up the soil earlier.
Of course if you can, get your hood house built before the first snow! But better late than never:) We had sunshine yesterday and the heat from the sun helped to melt much of the snow inside our hoop houses. And all of our plants are looking healthy and strong:)