What Is a Hoop House? Meaning, Structure and How It Works
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What is a hoop house? A hoop house is a simple growing structure made from a row of curved hoops covered with plastic film. It protects crops from cold, wind, hail and some pests, and it lets a grower plant earlier in spring and harvest later in fall. The term is closely tied to the phrase “high tunnel,” and extension publications often use the two names for the same kind of structure. This article explains what a hoop house is, how its parts fit together, how it captures heat, and where it differs from a greenhouse.
Quick answer
- A hoop house is a plastic-covered structure built over a frame of hoops, usually steel or PVC pipe.
- It works mainly by letting sunlight in and trapping warmth, rather than by adding heat from a heater.
- Extension sources describe it as a way to protect crops and extend the growing season.
- Many publications treat “hoop house” and “high tunnel” as interchangeable names.
What a hoop house is
A hoop house is a walk-in, plastic-covered tunnel used to grow vegetables, cut flowers and some fruit. The Purdue handbook on high tunnels states that “High tunnels (also called hoop houses) are low-cost, plastic-covered” structures, and it notes that they use the sun’s passive solar energy to protect plants from weather extremes and frost. The Utah State University extension answer gives a similar description, stating that “A high tunnel (or hoop house) is a plastic-covered structure used to protect crops and extend the growing season.”
The key idea is protection. A hoop house does not create a fully controlled indoor climate. Instead, it reduces the effects of cold nights, wind, rain and sudden temperature swings, so plants can stay in the ground when they would otherwise be exposed. For a home gardener, this often means earlier lettuce, spinach or radishes in spring, and a longer harvest of tomatoes, peppers or greens in autumn.
How the structure is built
Most hoop houses share the same basic parts. The first is the hoop, a curved bow that forms the main skeleton. The Nebraska EC308 publication describes the structure as “a series of hoops that are held in position with continuous lengths of supporting structural members (purlins and girts) and end walls with accessible doors.” The hoops carry the weight of the cover and resist wind and snow loads.
The second part is the covering. The Nebraska text notes that “The exterior covering is typically a greenhouse-grade polyethylene plastic that can either remain on the structure year-round or be removed during the heat of summer.” Some growers remove the film in hot months and leave the frame in place, which can protect plants from overheating while keeping the structure ready for cooler seasons.
The third part is the end walls. End walls hold the doors that let people and equipment in and out. The size of these openings matters. Large doors make access easy, but they also let warm air escape, so many designs include a smaller access door for use during the coldest weeks.
How a hoop house holds heat
A hoop house relies on the sun. Light passes through the plastic, warms the soil and plants, and the covering slows the loss of that heat. The USU answer explains that “High tunnels let in the heat coming from the sun and trap it, extending the warming into the cooler night.” Because the structure traps daytime warmth, it can keep the air inside several degrees warmer than the outside air on a cool night, although a hard freeze can still reach the plants during extreme cold.
Warm days can also cause problems. Inside a sealed hoop house, temperatures can climb quickly on a sunny afternoon. The same USU page advises that heat is managed by “opening the walls and doors to release it or by using shade cloth.” Growers often open vents or doors in steps as temperatures rise, and they place a simple thermometer at plant height, because the temperature near the ground can differ from the temperature at head height.
How a hoop house differs from a greenhouse
People often mix up hoop houses and greenhouses. The main difference is how heat is supplied. A greenhouse is usually heated with a furnace, electric heater or other energy source. A hoop house generally is not. The Purdue handbook states that “High tunnels are often defined as unheated” structures, and it describes how they depend on passive solar heat.
Structure and cost also differ. Hoop houses are usually simpler and less expensive to build than a glass or rigid-panel greenhouse. They rely on a bent frame and a film covering, and they are often placed directly on the ground rather than on a concrete foundation. This makes them easier to add to a home property, though the trade-off is less control over winter temperatures.
What hoop houses are used for
Hoop houses are most useful for crops that benefit from a longer season or from protection against rain, hail or pests. The USU answer notes that “High tunnels allow you to plant earlier and harvest later.” It also says that a high tunnel “can shield them from hail, heat, sunburn, and some pests.” Tomatoes can be planted about a month earlier in spring, and a grower can often keep ripening crops going later into fall.
Pest control is another use. When the structure is closed, it can keep out some insects, but open doors allow pests to enter. The USU page warns that “if doors and other openings are kept open, pests from the outside can get in.” A closed structure therefore works best when the door habits and air vents are managed on purpose.
Common mistakes to understand
A hoop house is not a shelter from every weather event. Heavy snow, strong wind and hail can damage the film or the frame if the structure is not built for local loads. The Purdue handbook discusses hoop spacing, pipe size and end wall design in detail, noting that narrower hoop spacing gives more support for the covering while wider spacing needs larger metal for strength. Choosing a design that suits local weather is part of understanding the structure.
Another mistake is assuming that the structure will keep plants warm without monitoring. Plants can overheat on a sunny day, and they can still freeze on a clear night if the air outside is cold enough. Watering needs also change, because the enclosed soil can dry out faster in warm conditions. Regular checks of temperature and moisture help the structure do its job.
Choosing a hoop house for a home garden
When deciding whether a hoop house fits a garden, start with the goal. A grower who wants to start salad greens two weeks earlier has different needs from one who wants to grow warm-season fruit in a cool climate. Site choice matters too. Good sun exposure, drainage and access to water make a larger difference than the brand of plastic or the number of hoops.
For more practical background on the garden plants and soils that often go into structures like this, the following guides on this site may help: how to use row covers explains a simpler and lower-cost way to protect plants, and how to make garden soil better covers soil preparation that applies in any enclosed bed. Both articles describe basic methods rather than specific structures.
How we chose
The sources listed below are university extension publications and an extension answer page. Each one describes hoop houses or high tunnels in a general way, and each was opened and checked on 2026-10-27. Retail pages were not used. Where the sources differ, for example on whether heat is added, the article notes the difference rather than choosing one view.
What we could not verify
The sources reviewed for this article describe the general structure and purpose of hoop houses. They do not give a single universal temperature rise, a fixed lifespan for the plastic film, or a standard cost per square foot that applies to every climate. Regional extension pages may give local guidance on snow loads and wind ratings, which this article does not cover in detail.
What the sources do not say
The sources do not state whether a hoop house will keep plants alive through a specific hard freeze in every region. They also do not provide a universal rule for how many vents or doors a structure needs. Readers planning a build should consult a local extension office for climate-specific design advice.
Frequently asked questions
Is a hoop house the same as a high tunnel?
In most extension publications, yes. The Purdue handbook states that “Hoop house is a term used interchangeably with high tunnel,” and the two names are widely used for the same plastic-covered structure.
Does a hoop house need a heater?
Many hoop houses do not have a heater. They rely on passive solar heat. Some growers add supplemental heat for severe cold, but an unheated design is the standard description in the sources reviewed.
How is a hoop house different from a greenhouse?
A greenhouse is usually heated by a separate energy source, while a hoop house generally depends on sunlight. Hoop houses are also usually simpler in frame and foundation.
Can a hoop house keep pests out?
It can reduce some pest access when it is closed. The USU page notes that open doors and other openings allow outside pests to enter, so the protection depends on how the structure is managed.
Do hoop houses need to be ventilated?
Yes, ventilation is important on sunny days. The USU answer advises opening vents and doors in steps as temperatures rise, and it recommends shade cloth if the structure becomes too hot.
Sources
- Utah State University Extension, “What is a High Tunnel?” https://extension.usu.edu/answers/articles/what-is-a-high-tunnel (opened 2026-10-27). Quoted: “A high tunnel (or hoop house) is a plastic-covered structure used to protect crops and extend the growing season.”
- Purdue University Extension, HO-296, “Indiana High Tunnel Handbook.” https://www.extension.purdue.edu/extmedia/HO/HO-296.pdf (opened 2026-10-27). Quoted: “High tunnels (also called hoop houses) are low-cost, plastic-covered.”
- University of Nebraska-Lincoln Extension, EC308, “High Tunnel Design, Site Development, and Construction.” https://extensionpubs.unl.edu/publication/ec308/2015/html/view (opened 2026-10-27). Describes the hoop frame and polyethylene covering.
