Hoop House Season Extension: Double Your Growing Season on a Budget

What Is a Hoop House?

A hoop house is a low-cost, unheated structure that extends your growing season by trapping solar heat. It's essentially a greenhouse without the foundation — a series of metal or PVC hoops covered with plastic sheeting, sitting directly on the ground.

The key difference between a hoop house and a greenhouse is that a hoop house has no insulation, no heating system, and no ventilation beyond rolled-up sides. It's a passive solar collector that raises the temperature inside by 10–30°F above the outside air. That temperature bump is the difference between your kale surviving a 20°F night and freezing solid.

Why Build a Hoop House?

Cost. A well-built 8×24 hoop house costs $150–300 in materials. A comparable greenhouse with foundation and ventilation costs $2,000–5,000+.

Simplicity. You can build one in a weekend with basic tools. No concrete pouring, no electrical work, no specialized skills.

Effectiveness. A properly built hoop house extends your growing season by 4–8 weeks on each end of the season. That's 2-4 extra months of fresh greens and hardy vegetables.

Portability. When the season ends, you can take it apart and move it. It's not a permanent structure, which means you can rotate its location to avoid soil fatigue.

Materials List

For an 8×24 foot hoop house:

Frame:

• 100 feet of ½-inch EMT (electrical metallic tubing) conduit — $30–40. This is your hoop material. It's strong, flexible, and inexpensive. You'll bend it into arches.
• Alternative: ½-inch PVC Schedule 40 pipe — cheaper but weaker. Works in mild climates.

Fasteners:

• 8 EMT conduit straps (U-brackets) — $8. These go in the ground and hold the hoop ends.
• 48–60 feet of ¼-inch rebar or PVC pipe for anchoring — $10. These go through the straps and into the ground.
• 20–30 feet of ¾-inch Schedule 40 PVC pipe for end frames — $10.

Covering:

• 30-mil greenhouse-grade polyethylene film, 12 feet wide × 25 feet long — $40–60. Don't use cheap nursery shade cloth. Use actual greenhouse film.
• Alternately, 6-mil builder's plastic works but won't last more than one season.

Anchoring:

• Landscape staples (U-shaped wire) — $5. These hold the plastic to the ground.
• 4×4 posts for end frames — $8.
• Hinges or bungee cords for door ventilation — $10.

Tools:

• Hand bender for EMT conduit — borrow or rent ($15/day). Or buy for $40–60 if you plan to build more.
• Drill, screwdriver, utility knife, measuring tape, shovel.

Total cost: $150–250 for a durable, 5+ year hoop house.

Building Your Hoop House

Step 1: Choose the site. South-facing slope is ideal (captures maximum sun). Avoid low spots where cold air settles. Get full sun from 9 AM to 3 PM year-round. Orient the long axis east-west.

Step 2: Lay out the footprint. Mark an 8×24 rectangle in the ground. Use string and stakes. Check that corners are square (measure diagonals — they should be equal).

Step 3: Install the end frames. At each short end of the rectangle, drive two 4×4 posts (8 feet tall) into the ground 2 feet deep. Connect them with a cross-piece near the top. Cut a door opening (2.5 feet wide) on one end for access.

Step 4: Bend the hoops. Bend the EMT conduit into arches using the hand bender. Each hoop should span 8 feet wide and reach about 6 feet tall in the center. You'll need 6–8 hoops spaced 3 feet apart along the 24-foot length.

Step 5: Install the hoops. Slide one end of each hoop into the EMT strap at one end frame and the other end into the strap at the opposite end frame. Space hoops 3 feet apart. The center hoop should be highest — about 6 feet. Side hoops should be slightly lower — about 4 feet at the edges.

Step 6: Anchor the hoops. Drive rebar through the EMT straps and 18–24 inches into the ground. Space rebar every 2 feet along each side. This anchors the entire structure.

Step 7: Cover with plastic. Roll the greenhouse film over the hoops. Center it so there's equal overhang on each side (about 1–2 feet of extra on each side to secure to the ground).

Step 8: Secure the plastic. Use landscape staples along the edges to anchor the film to the ground. Fold the edges under as you staple to create a clean, secure attachment. Leave the edges loose on the south side so you can roll them up for ventilation during warm days.

Step 9: Add ventilation. Roll up the plastic on the south side (or both sides) on warm days. You can create rolling vents with rebar threaded through the plastic edge and a wooden handle. Or use simple bungee cords to hold the plastic up.

Step 10: Add a door. Install a simple door frame in one end of the hoop house. A hinged door or just a heavy curtain of plastic strips works fine.

What to Grow in a Hoop House

Hoop houses keep things 10–30°F warmer than outside. In Zone 7a, that means:

Early spring (March–April):

• Lettuce, spinach, arugula, kale — harvest 4–6 weeks earlier than outside
• Peas, radishes, carrots — planted 2 weeks before last frost
• Onion sets — planted 3 weeks before last frost

Late fall (October–November):

• Kale, collards, spinach — planted in August, overwintered under the hoop house
• Garlic planted in fall will establish roots before winter
• Cover crops can be grown longer for more biomass

Winter (December–February):

• In mild winters (above 15°F), you can grow spinach and kale under the hoop house even in January
• In harsh winters, use the hoop house to protect cold frames or extend the fall harvest

Temperature Management

The hoop house's biggest challenge is overheating. On a sunny 50°F day, the inside can reach 90°F+ within an hour. Here's how to manage it:

Ventilation is everything. Roll up the sides whenever the inside temperature exceeds 70°F. Even 2 inches of opening provides significant cooling.

Shade cloth. On particularly bright spring days, drape 30% shade cloth over the hoop house to reduce heat buildup.

Watering schedule. Water in the morning, not the afternoon. Wet soil absorbs heat more slowly than dry soil, which helps moderate temperatures.

Insulation at night. On cold nights, cover the hoop house with a floating row cover (agribon or similar) for an extra 5–10°F of protection.

Hoop House vs Cold Frame vs Greenhouse

Feature	Hoop House	Cold Frame	Greenhouse
Cost	$150–300	$50–150	$2,000–5,000+
Size	8×24 ft	3×6 ft	Various
Heat gain	10–30°F	5–15°F	20–40°F+
Durability	5–10 years	3–5 years	15–20 years
Growing season extension	4–8 weeks each end	2–4 weeks each end	Full year
Best for	Season extension, bulk greens	Hardy crops, baby greens	Tropical crops, starting seeds

If you're growing on a small scale and want to extend the season: hoop house. If you just want a few heads of lettuce in November: cold frame. If you want to grow year-round in Zone 7a: greenhouse (or a hoop house + cold frame combo).

The Bottom Line

A hoop house is the single most cost-effective season extension tool you can build for a home garden. It costs less than most lawnmowers, takes one weekend to build, and can add 2–4 months to your growing season.

For Zone 7a gardeners, that means fresh lettuce in March and hardy greens in December. In a region where the growing season runs April through October, those 2–4 extra months on each end are transformative.

Build it small (8×24 is plenty for a family). Build it simple. Use EMT conduit. And always, always plan for ventilation before you plan for heating.