Extending Your Garden's Season: A Simple Guide to Building and Using a Hoop House

Tired of saying goodbye to your garden when the first frost rolls in? Imagine harvesting crisp lettuce, sweet carrots, and even fresh herbs long after your neighbors have packed it in for the season. The secret is a hoop house—a low-cost structure that traps sunlight, shields from frost and cold winds, and stretches your harvest window by weeks or months. Think of it as your garden's cozy winter jacket.

A hoop house can be built for under 00 and doesn't require heat, electricity, or greenhouse technology. It's one of the most practical tools for home gardeners who want to extend their season.

What Is a Hoop House?

A hoop house (also called a polytunnel, hoop tunnel, or high tunnel) is simply heavy-duty plastic stretched over arched steel or PVC hoops. It's not heated and doesn't have artificial lighting. Instead, it works by trapping solar radiation to increase the temperature inside while providing shelter from frost and cold winds.

The key difference between a hoop house and a greenhouse is the complexity and cost. A greenhouse typically has windows, ventilation systems, and sometimes even heating. A hoop house is essentially a plastic tunnel that does one job really well: it creates a microclimate that's several degrees warmer than the outside air.

The easiest way to make a small tunnel is to put metal posts into the ground along the sides of your garden bed, slide segments of PVC pipe over one post and arch over the garden bed to the opposite post, then stretch the polyethylene plastic across the arches. You can also build over a raised bed, using a few hoops per bed.

Why Use a Hoop House?

Hoop houses provide three main benefits:

Frost Protection - Even a light frost can kill lettuce and spinach. A hoop house keeps frost away from your plants entirely.

Temperature Increase - Soil temperatures inside a hoop house are several degrees warmer than those outside. This allows for consistent growth even when outdoor temperatures dip below freezing.

Wind Protection - Cold, drying winds damage plants and increase water loss. The plastic covering blocks wind and creates a more stable environment.

The result is that you can grow crops weeks earlier in spring and weeks later in fall. Some gardeners harvest fresh greens through winter in cold climates.

Choosing Your Design

Before you start building, decide on the basic approach.

Stationary vs. Mobile

A stationary hoop house stays in one place. It's simpler to build and can be larger. A mobile hoop house sits on skids or rails and can be moved across your garden plots. Mobile designs increase flexibility and let you rotate soil without disturbing the structure.

For home gardeners, a stationary hoop house 10x20 feet or similar size is usually sufficient. You can always scale up or add more tunnels later.

Size Considerations

Start with what fits your space and budget:

• Small (4x8 feet): Fits over a single raised bed, good for greens
• Medium (10x20 feet): Enough space to walk inside, covers multiple beds
• Large (14x40 feet): Professional scale, requires more materials and effort

For most home growers, a medium-sized hoop house in the 10x20 foot range is a sweet spot. You get enough room to work inside without requiring excessive materials.

Building Your Hoop House

Here's a simple design based on approaches used by experienced growers. This is a 10x20 foot hoop house built with PVC sleeves and rebar.

Materials List

You'll need:

• 10 4-foot pieces of rebar (concrete reinforcement bar)
• 2 2-foot pieces of rebar
• 7 10-foot pieces of ½-inch schedule 40 PVC pipe, cut into 22-inch lengths (you need 10 of these pieces)
• 2 50-foot lengths of strong twine or thin rope
• 2 6-foot lengths of rope
• 20 8-inch zip ties
• 32x15-foot piece of greenhouse-grade plastic sheeting (available online or at garden supply stores)
• 10 large binder clips (available at office supply stores)
• Heavy-duty plastic sheeting for covering

Construction Steps

1. Set the Posts Drive the 4-foot lengths of rebar 2 feet into the ground in two parallel lines about 8 feet apart. Within each row, space the posts about 5 feet apart. You should have 10 posts total, 5 in each row.

2. Add PVC Sleeves Slip a 22-inch sleeve of PVC pipe over each one of the rebar posts. The PVC protects the rebar and makes the structure easier to assemble.

3. Create the Hoops Take the 10-foot lengths of PVC pipe and bend them into hoops. Slip one end over the remaining 2 inches of rebar projecting above each sleeve on one side, then bend it over to the corresponding rebar in the other line of posts. It will take some force to get them onto the posts. The highest point of each hoop should be about 5 feet tall.

4. Create Anchor Points Take a zip tie down to the base of the rebar posts and loop it around. Slip another zip tie into the loop but don't cinch it tight. You're creating one in a series of loops that serve as anchor points for the plastic cover. Make these loops at the base of all ten posts.

5. Add a Ridge Pole Take the two 2-foot rebar posts and pound them into the ground about 5 feet out from either end of your hoop house. They should be tipped back at an angle from the structure. Leave 6 inches showing, and put something bright on the end so you can see them in snow.

6. Install the Center Rope Take a piece of cord or twine and tie it to one of those end posts. Loop it around the first PVC pipe arch at the highest point in the center. Continue looping it around each of the five arches. Secure it to the second rebar stake at the opposite end with no slack. This creates a ridge pole to prevent sagging.

7. Add the Plastic Cover Drape your plastic sheeting over the arches and center rope beam. Unroll it so it extends a bit past each end.

8. Secure the Plastic Take one of the 50-foot lengths of rope and knot it around the zip tie at one end of your hoop house. Thread it over the hoop and around the zip tie on the second post on the opposite side. Continue staggering the rope in a zig-zag pattern until you reach the other end of the hoop house. Take the second 50-foot length of rope and stagger in the opposite direction to create a crisscross pattern. This is like lacing up a shoe.

9. Finish the Ends Gather the excess plastic sheeting on the ends and bunch together, then bind with one of the 6-foot lengths of rope. You can roll these ends up during warmer days for ventilation.

10. Add Ventilation To let out excess heat, you'll want to be able to roll up the sides of the plastic. Secure roll-ups on each side by clamping the rolled plastic tightly with binder clips. Keep five or so clips on each side so you can adjust them. Roll it down to keep the heat in, roll it up when you need ventilation.

Your hoop house is ready. With these materials, you should spend around 5 and about an hour of your time.

Managing Temperature and Ventilation

A hoop house can get hot even in winter. On sunny days with outdoor temperatures in the 40s or 50s, temperatures inside can reach 80 degrees or more. Managing this heat is essential.

Roll-Up Sides

Keep the ends of your hoop house unrolled during cold weather. During warm, sunny days, roll up the sides to let hot air escape. You can do this incrementally—roll up one side first, then the other if needed.

End Doors

Leave the end doors closed during cold nights to retain heat. Open them during the day if temperatures inside get too warm. The binder clips make this adjustment quick and easy.

Watch the Weather

On cold nights, close everything up. On sunny afternoons, open it up. If a major cold snap is coming (below 10 degrees Fahrenheit for extended periods), you may need to add extra protection like row covers inside the hoop house to shield tender plants.

What to Grow in Your Hoop House

A hoop house is ideal for crops that tolerate cool temperatures and don't need hot summer conditions.

Greens That Thrive

From early November through April in many climates, you can grow:

• Lettuce varieties specifically bred for winter, such as Winter Density Bibb romaine and Winter Marvel butterhead
• Mesclun mixes
• Baby kale
• Arugula
• Spinach
• Scallions
• Radishes
• Parsley and dill
• Claytonia (miner's lettuce or winter purslane)
• Mache (corn salad or lamb's lettuce)

These greens thrive in the cool conditions and will actually get sweeter as temperatures drop.

Root Crops

You can also grow:

• Carrots
• Turnips
• Radishes
• Beets

These may take longer in cold weather but will continue to grow inside the hoop house.

What to Avoid

Don't plant heat-loving crops like tomatoes, peppers, or cucumbers in a hoop house during winter. They need the hot conditions a heated greenhouse provides. Save them for summer, when your hoop house can serve as a shade structure instead.

Maintenance and Lifespan

The plastic on your hoop house will need replacement every few years. UV exposure and weathering degrade the material over time. When the plastic becomes brittle or develops holes, it's time to replace it.

Plastic Care

• Cover your hoop house with tarps during summer if you're not using it. This prolongs the life of the plastic by protecting it from UV damage.
• Remove end doors during off-season to prevent wind damage.
• Check for tears or loose areas periodically and patch them if needed.

Seasonal Adjustments

During summer, you can remove the plastic entirely and let the structure rest. Or you can keep it in place and use it to shade out crops that prefer cooler conditions.

Is a Hoop House Worth It?

A hoop house requires investment—both money and planning—but the returns can be substantial for home gardeners.

Cost Breakdown

Based on the design above, your hoop house costs:

• Rebar: ~0
• PVC pipe: ~5
• Plastic sheeting: ~0
• Rope, zip ties, binder clips: ~0

Total: around 5 to 00 depending on your location and what you already have.

Benefits

• Extend your harvest by weeks or months
• Protect against unexpected late spring or early fall frosts
• Reduce or eliminate the need to buy greens in winter
• Create a productive growing space even in cold weather

The Planning Factor

A hoop house does require you to reset your planting calendar and think about planting times differently. You'll need to plant in the fall for winter harvest, or early in spring for an extended spring harvest. But for gardeners willing to plan ahead, this is a small price for fresh greens year-round.

Getting Started

Start small with a hoop house and taste the difference fresh-picked produce makes—even in January. You don't need a huge structure or expensive equipment. A simple 10x20 foot hoop house built with basic materials can transform your winter garden from dormant to productive.

The best time to build is before you need it. Construction goes quickly when you're motivated, but planning and gathering materials is easier when there's no rush. Aim to have your hoop house ready a month or two before you expect to start using it.

For more inspiration, look into designs by experienced growers like Eliot Coleman, whose Four-Season Harvest describes practical approaches to year-round growing with unheated structures.

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— C. Steward 🥕