Step-by-step instructions for building a cheap hoop house for reliable frost protection.
A DIY row cover tunnel is one of the easiest and cheapest ways to protect crops from frost and extend your growing season. With simple materials like PVC pipe and greenhouse plastic, you can build a low tunnel greenhouse in just a few hours and start planting earlier in spring—and harvesting later into fall.
Why Use a Row Cover Tunnel?
A row covering allows you to plant earlier in the spring, protecting your young seedlings from harsh weather. And then you can harvest later in the fall when strong winds and snow can take their toll on even the hardiest crops. A simple row cover can protect your plants from the worst of the winter weather and dramatically extend your growing season. See more great reasons to use row covers.
Row covers can be expensive to buy, but they don’t require a lot of materials or time to make your own, and the benefits are well worth the effort.
Materials Needed to Build a DIY Row Cover Tunnel
For this project you’ll need some PVC water piping about half an inch (12 mm) wide, plus some 20-inch (50 cm) long lengths of rebar, two pipe caps, and some U-bolts or garden wire. To cover the tunnel, you’ll need some greenhouse plastic or strong polyethylene, some pipe insulation or similar soft material, and spring clamps to hold the cover in place.
The only tools you’ll need are a hacksaw and a hammer.
How to Build a PVC Hoop House (Step-by-Step)
Hammer in the Supports
Begin by hammering in the lengths of rebar at equal distances along your garden bed. These will support the hoops. Space them a maximum of 3 feet (90 cm) apart along each side. Leave 6 to 8 inches (15–20 cm) of rebar above ground.
Make the Hoops
Now cut lengths of pipe to make the hoops. The hoops should be long enough to bend into a half circle, allowing a little extra to give enough height for plants growing near the sides. Flex the hoops into position onto their rebar supports.
Add the Ridgepole
The ridgepole links the hoops together and stabilizes the structure. It will also support the cover to prevent sagging. Measure it out so that it slightly protrudes at each end of the hoop house. Cut to size, then cap or tape the ends to stop them snagging the cover. Secure them onto the hoops with U-bolts or thick garden wire.
Cover the Tunnel
Cover the hoop house with your polyethylene. You may need to cut this to size first. Secure it to the hoops using short lengths of soft rubber tubing or pipe insulation, slit and open it out lengthways. This protects the polyethylene from the clamps, which follow to hold it all firmly in place.
Secure the Cover in Place
Weigh down the edges of the polyethylene with bricks. For a more thorough seal you can wrap the sides of the cover around a length of conduit or bamboo cane, which can then be pegged down at regular intervals using tent pegs. The ends of the cover should be pinned or weighed down whenever cold or frosty weather is forecast. This will also stop the wind from getting in underneath and tearing the cover off.
Alternative Method: Using Cattle Panels
You can also make a row cover using heavy-gauge mesh or cattle panels. Simply cut the panel to size using bolt cutters, then flex the panel into shape. Don’t leave any sharp edges, which could snag the cover—cut them off or cover with old hosepipe slit along its length to create a seal. Push or peg the tunnel into position, then cover and secure as before.
Frequently Asked Questions
How much frost protection does a row cover tunnel provide?
A row cover tunnel can protect plants from 2° to 8°F of frost, depending on the thickness of the covering material. Lightweight row covers offer basic frost protection, while thicker greenhouse plastic or heavy-duty fabric provides more insulation. Properly sealing the edges improves protection.
What is the difference between a row cover and a hoop house?
A row cover typically refers to the protective fabric or plastic placed over crops, while a hoop house describes the structure made from PVC pipe, metal hoops, or cattle panels that supports the covering. Together, they form a low-tunnel greenhouse system.
What crops grow best under a row cover tunnel?
Cool-season crops perform best under row covers. These include:
Row covers are especially helpful for extending early spring planting and late fall harvests.
How far apart should hoops be spaced?
Hoops should be spaced no more than 3 feet apart along the bed. Closer spacing improves stability in windy conditions and prevents sagging when snow or rain collects on the cover.
Can I use PVC pipe for a hoop house?
Yes, ½-inch PVC pipe is commonly used for DIY hoop houses because it’s flexible, inexpensive, and easy to cut. It bends easily over rebar supports to create sturdy hoops.
How long does greenhouse plastic last?
Standard greenhouse plastic typically lasts 1–4 years depending on UV exposure and quality. Thicker, UV-stabilized plastic will last longer than basic polythene sheeting.
Do row covers need ventilation?
Yes. On sunny days, temperatures inside a row cover tunnel can rise quickly. Lift or vent the sides during warm weather to prevent overheating and reduce humidity buildup.
Are row cover tunnels worth it?
Absolutely. A DIY row cover tunnel is one of the most affordable ways to extend your growing season, protect plants from frost, reduce pest damage, and increase harvest yields.
How to Use Row Covers in Garden Planning
Adding row covers to your cropping schedule will help you to extend your growing season.
Tip: Our Garden Planner allows you to add these and other protected structures to your plan with ease. Simply select “Structures” from the drop-down menu, then scroll through the selection bar to choose the type of crop protection you want to use— for instance, a hoop house. Click to pick it up, move the cursor to where you want it on your plan, then click or drag it out to place it. You can resize or rotate the tunnel using the handles. The accompanying plant list automatically adjusts the sowing and harvest dates to take account of the extra protection from frost that the tunnel gives. You can adjust these preset dates via the information box accompanying the structure description.
Ready to extend your growing season? Build your own DIY row cover tunnel this weekend—and let us know in the comments what crops you’re protecting!
More Like This
Hi Nancy,
Using a row cover is a great way to extend the growing season in both the spring and fall, but when your strawberry flowers begin to bloom, you should remove the row covers to allow for pollination. Depending on when that happens and the current weather, you can remove the row covers in the morning for the day when pollinators are active and then replace them at night if there is any chance of adverse weather.
Check out our Planting Calendar to see recommended dates for your area!
Row covers are made of polypropylene which lets light and rain and irrigation through to reach the plants and soil. It also traps heat. However, it will protect plants from frost damage down to 28 degrees F. Make sure you get the regular all-purpose row covers, not summerweight which doesn't protect from frosts.
