GuideGreenhouses
Make a Mini Hoop House for a Raised Bed
A low hoop house turns an ordinary raised bed into a small greenhouse for a few weeks at each end of the season. Flexible hoops hold clear plastic over the plants, warming the soil and keeping off frost, wind and heavy rain. It goes up in an afternoon and comes down when summer arrives.
What you will build
You will fix short pipe sleeves to the inside of the bed, bend flexible hoops into them every 2 ft (60 cm) or so, tie a ridge pole along the top to stop the hoops from wobbling and stretch greenhouse film over everything. Clips hold the film to the hoops, and the long sides can be rolled up for venting.
The design here is for a 4 × 8 ft bed, but it scales to any length: just add more hoops. Keep the height low, about 3 ft (90 cm), so wind does not catch it.
Real-world examples
Photos of similar builds by other people, shared under open licenses. They show the idea in practice; the details differ from this guide.
Materials
- 5 lengths of flexible plastic conduit or polyethylene tubing, about 10 ft (3 m) each, for the hoops
- 10 short pieces of rigid pipe a size larger than the hoops, about 12 in (30 cm) long, as sleeves
- Pipe clips or plumbing straps with screws to hold the sleeves to the bed
- 1 straight batten or pipe 8 ft (2.4 m) long for the ridge
- Cable ties
- Clear greenhouse film (UV-stabilised) about 12 × 14 ft (3.6 × 4.3 m)
- Snap clamps or plastic clips made for hoops (about 15–20)
- 2 battens or lengths of pipe to weigh down the long edges
Tools
- Tape measure
- Drill/driver
- Hacksaw or pipe cutter
- Scissors or utility knife
- Gloves
Step by step
1Fix the sleeves to the bed
Screw the short rigid pipe sleeves upright to the inside of both long sides of the bed, opposite each other, every 2 ft (60 cm). Use two straps per sleeve so they cannot twist. The bottom of each sleeve can sit on or just in the soil.
2Bend in the hoops
Push one end of a hoop into a sleeve on one side, bend it over the bed and push the other end into the opposite sleeve. Trim the hoops so they all reach the same height; a ruler held across the top of the bed makes this easy.
3Add the ridge pole
Lay the ridge batten along the tops of the hoops and fix it to each one with a cable tie, or two crossed ties. The ridge stops the hoops from leaning in the wind and keeps them evenly spaced.
4Stretch the film over
Pick a calm day. Drape the film over the hoops so it hangs evenly on both sides and overlaps both ends. Clip it to the end hoops first, then to the middle ones, pulling it gently tight as you go so it does not flap.
5Close the ends
Gather the film at each end like the end of a wrapped sweet, and tie or weigh it down. You can open one end on warm days for ventilation.
6Weigh down the long edges
Roll each long edge of the film around a batten or pipe and let it rest on the ground beside the bed. To vent, roll the batten up and clip it to the hoops; to close, let it down again.
Tips for a better result
- Open the sides on any sunny day above about 50 °F (10 °C); temperatures under plastic climb very fast.
- In midsummer, swap the film for insect netting or shade cloth on the same hoops.
- Water before you close it for the night; moist soil holds heat better.
- Store the film dry and out of the sun when you take it down, and it will last several seasons.
Common mistakes to avoid
- Building the hoops too tall, so the cover catches the wind like a sail.
- Leaving it closed on a sunny day and cooking the plants.
- Using ordinary clear plastic sheeting instead of UV-stabilised greenhouse film; it turns brittle within a season.
- Skipping the ridge pole, so the hoops lean and the film sags and collects water.
Safety
- Cut pipes with a hacksaw or pipe cutter held firmly, and smooth sharp ends.
- Check the cover after strong winds and snowfall, and brush off heavy snow.
General guidance only. Follow the instructions for your tools and materials and your local rules, and use a qualified professional for electrical, gas and structural work.
Finishing up
A mini hoop house is the cheapest way to win a few extra weeks at both ends of the growing season. Start with early salads and radishes in spring, then use it again in autumn for hardy greens like spinach, kale and lamb's lettuce.
About this guide: written by the DIY Outdoor Builds editors from general, widely used building and gardening practice. Text and illustration © DIY Outdoor Builds. Photos are by the people credited under each one, used under their licenses. Found an error? Let us know.
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