A Pit Greenhouse: What Is It?

Pit greenhouses, also known as underground greenhouses or Walipinis, are unique structures used by cold climate gardeners to extend the growing season. These structures are built below the natural ground level and are partially or fully sunken into the ground. The term “walipini” comes from the Aymara Indian word for a “place of warmth”, and it refers to a rectangular pit dug into the ground with a double layer of plastic covering it.

In Bolivia, farmers use these greenhouses to protect crops from high altitudes in the Bolivian mountains. These earth-sheltered greenhouses tap into the thermal mass of the earth, requiring less energy to heat their interior than similar-sized greenhouses. At a depth of four feet, the Earth retains a temperature of roughly 50 degrees year-round, almost 10 degrees warmer than that of an above-ground greenhouse.

Pit greenhouses are extremely energy efficient, as they are essentially a hole dug into the ground with an attached glass structure. At a depth of four feet, the Earth retains a temperature of roughly 50 degrees year-round, almost 10 degrees warmer than that of an above-ground greenhouse. Pit greenhouses can be an energy-efficient greenhouse structure, particularly in cold and windy climates, and can be designed using Sturdi-built materials.

In summary, pit greenhouses are a cost-effective and effective way to grow plants in a controlled environment. They are buried six to eight feet into the ground and covered with a glazed roof, making them ideal for cold climate gardens.

Why underground greenhouses?

Building a foundation with a downward slope can help capture heat in colder months, while black water barrels can store solar heat gain during sunny days. Radiation and emissivity are crucial factors in greenhouse design, with blacker materials absorbing more light and heat. Reflecting light with white or shiny surfaces can increase brightness, spreading productive growing light. Materials like stone and metals transfer heat effectively to cool areas, while insulators can slow heat transfer to cold areas. Convection occurs when hot air rises and leaves cool areas near the ground.

What is the temperature in a sunken greenhouse?

Pit greenhouses are energy-efficient, as they are essentially holes dug into the ground with an attached glass structure. They maintain a temperature of around 50 degrees year-round, which is 10 degrees warmer than an above-ground greenhouse. To maintain a 70-degree temperature, only 20 degrees need to be raised. Most plants require constant 60-degree temperatures, so pit greenhouses stabilize the temperature, reducing energy costs and allowing for year-round plant nurturing.

Plant selection is crucial, but allowing the greenhouse’s temperature to fall below 50 degrees is not recommended. Cold weather crops like kale and broccoli can grow lower temperatures, while warm weather plants like peppers and tomatoes require higher temperatures. Plants are often grown directly in the soil in pit greenhouses, but extra depth is needed for drainage and the floor is sloped to encourage water run-off.

What is the temperature in an underground greenhouse?

Pit greenhouses are energy-efficient, as they are essentially holes dug into the ground with an attached glass structure. They maintain a temperature of around 50 degrees year-round, which is 10 degrees warmer than an above-ground greenhouse. To maintain a 70-degree temperature, only 20 degrees need to be raised. Most plants require constant 60-degree temperatures, so pit greenhouses stabilize the temperature, reducing energy costs and allowing for year-round plant nurturing.

Plant selection is crucial, but allowing the greenhouse’s temperature to fall below 50 degrees is not recommended. Cold weather crops like kale and broccoli can grow lower temperatures, while warm weather plants like peppers and tomatoes require higher temperatures. Plants are often grown directly in the soil in pit greenhouses, but extra depth is needed for drainage and the floor is sloped to encourage water run-off.

What size is an underground greenhouse?

The location of your Walipini greenhouse depends on the size and space needed for plant growth and a small area for entry. The recommended size is 8 x 12 feet, with the bottom at least 5 feet above the water table. To ensure the roof receives light during winter, it should be set up East to West, with the roof facing South.

After determining the location, start digging by plotting the area above ground and digging at least 2 feet deeper than desired depth. Keep soil close to prop up the roof. The walls of your Underground Greenhouse should have a minimum 6-inch slope from the roof to the floor to reduce soil crumbling and caving. Layering the walls with clay or bricks can help prevent erosion and stabilize the building.

What are three main greenhouses?

The World Meteorological Organization (WMO) reported in 2021 that atmospheric levels of carbon dioxide, methane, and nitrous oxide reached record highs. These gases trap heat from the sun, contributing to the greenhouse effect. Human activities’ emissions primarily contributed to global warming of 1. 1°C. Carbon dioxide levels in 2021 were 149 higher than pre-industrial levels. From 2011 to 2020, 48 of these emissions were in the atmosphere, 26 in the ocean, and 29 on land.

What are the disadvantages of glass greenhouses?

Glass greenhouses are known for their durability and strength, but they are prone to breakage in extreme weather conditions. Polycarbonate greenhouses, on the other hand, are highly durable and virtually unbreakable, making them ideal for unpredictable weather or areas with vandalism concerns. Glass panels provide excellent light transmission, allowing plants to receive ample sunlight for optimal growth.

Additionally, glass offers superior insulation, ensuring stable temperatures and reducing heating costs during colder months. Overall, glass and polycarbonate greenhouses offer different advantages and benefits for greenhouse construction.

What are the benefits of a sunken greenhouse?

Sun-Pits, or earth-sheltered greenhouses, originated in New England around the 18th century and are large versions of cold frames used to protect plants from winter cold. These greenhouses collect and retain warmth from the daytime sun and store it in the ground, releasing it as air temperatures drop at night. Full-size pit greenhouses are designed to take advantage of the constant temperature of the earth several feet below ground.

Walipini, originating in South America, are typically sunk up to 8 feet into the ground with a translucent roof angled to receive maximum sunlight on the winter solstice. This design was popularized in the early 2000s after US missionaries traveled to Bolivia to help the indigenous population improve their access to fresh food. Walipini take advantage of passive geothermal and passive solar heating, maintaining a steady temperature of about 55 degrees even when winter nights fall below freezing. Earthen walls absorb heat from the sun during the day and release it during colder nights, providing a comfortable interior environment for growing food year-round.

What are 3 disadvantages of greenhouse effect Why?

Human activities are increasing global temperature, posing a threat to our survival. The greenhouse effect, once a great ally, is now a threat due to its impact on soil degradation and desertification. This is causing the disappearance of islands and coastal cities. The melting of glacial masses and the proliferation of hurricanes are also consequences of global warming. The rising sea levels are also contributing to the desertification of arid areas.

Why is a glasshouse called a greenhouse?

The term “greenhouse” refers to a plant-keeping house designed to protect plants from cold weather. The terms conservatory, glasshouse, and hothouse were often used interchangeably, with plants planted in free soil and in “beds and borders” in a conservatory, and plants kept in pots or tubs in a greenhouse. The term “hothouse” or stove was also used to describe the part of the greenhouse with higher temperatures.

The modern greenhouse, which allowed for artificial control of light and temperature, was possible only after 1700 when glassmaking improved and glass became cheaper. Manufacturers used a pouring process instead of blowing glass. The earliest greenhouses had large window openings integrated into masonry, wood, or stone structures. These were replaced by iron-and-glass houses around the turn of the 19th century, which revolutionized greenhouse construction by allowing wide-span and filigree structures that allowed more light.

Greenhouse construction began as early as John Bartram’s 1739 description of Westover, Virginia, on the James River and continued through the mid-19th century at sites ranging from elite houses to modest dwellings and greenhouses. The pervasiveness of greenhouses reflects an interest in keeping exotic plants and extending the growing season by providing a supportive environment for seed starting, fruit ripening, and flower forcing.

What is the difference between a greenhouse and a glasshouse?

A greenhouse is a structure used for growing plants or vegetables, typically covered with glass or plastic films. It is also known as a polyhouse, a greenhouse, or a shade house or screen house. When developing or expanding a greenhouse, it is crucial to choose structures that meet your needs, such as light transmission, natural ventilation, internal space, structural efficiency, condensation run-off, heating requirements, and cost. Investing in suitable structures ensures a successful greenhouse enterprise.

What is the most efficient type of greenhouse?

Twin-wall polycarbonate covers are more resistant to temperature variability and last more than double as long as poly film. However, greenhouses lose a lot of heat during winter months, especially at night. To improve heat retention, use winter-ready poly film glazing, which is heavier and more opaque, which attracts heat during the day and reflects it back into the greenhouse at night. Another option is installing a water wall for passive solar heat, which uses polyethylene bags filled with water to absorb solar energy during the day and radiate it into the greenhouse at night.