Growing Underground: Walipini Greenhouses

Weather extremes, from harsh winters to scorching summer heat, can be brutal for gardeners.

But what if we told you there’s a way to grow fresh produce year-round, no matter what kind of climate you live in? Enter the Walipini greenhouse.

The word “Walipini” comes from the Aymara language of Bolivia and Peru; it means "place of warmth.” But really, these greenhouses can provide a cool gardening haven, too.

Positioned about 6-8 feet underground, Walipinis provide a stable microclimate for plants. The walls are typically earthen, and the structure is covered with one or more layers of polyethylene glazing.

The Walipini concept was developed mostly in Bolivia by the Benson Institute, a part of Brigham Young University, to help local farmers extend their growing seasons in the harsh Andean climate. Over time, the concept gained popularity worldwide.

Underground gardening comes with a unique set of pros and cons. We’re going to explore those considerations, and, for those of you who think a Walipini greenhouse just might be a good fit, we’ll provide some tips for establishing and gardening in one.

Walipini upsides

One of the biggest pluses of a Walipini greenhouse is it lets you grow plants throughout the year. Their underground setting protects plants from dramatic highs and lows in temperature — along with strong winds, frosts, and snow.

Walipinis are energy efficient, too. They need minimal heating or cooling because of the natural insulation they have in the earth. That can mean energy and cost savings for you.

The enclosed, controlled environment of a Walipini can also reduce pests and diseases that are more common in above-ground structures, like aphids, whiteflies, and powdery mildew.

Plus, if you need it, a Walipini can give you more room for gardening. Its underground construction doesn’t take up much above-ground space, making it a good fit for small properties.

Walipini downsides 

While a Walipini can reduce your energy costs, building one can involve significant upfront costs. Not only that, but depending on your location, constructing a Walipini might require navigating complex building codes and obtaining permits. 

There is a risk of flooding with a Walipini. You would need to make proper drainage a high priority. And because the greenhouse is in an enclosed, insulated environment, it could be subject to excess humidity.

Another potential challenge could be going in and out of your Walipini. It can be a bit challenging to access them, especially for anyone with mobility issues.

Finding the right location

If you decide you’d like to set up a Walipini greenhouse, put some thought into where you want it to be. 

It should be oriented to get the maximum amount of sun exposure possible, especially during the winter. Ideally, the longest wall should face south (in the Northern Hemisphere) to capture the most sunlight. It also would help to avoid obstructions like trees or buildings that could cast shade on your greenhouse.

As we mentioned, good drainage will be important to prevent water pooling and flooding. Rule out areas prone to standing water. 

You’ll also want to make sure you’re picking a spot in a low water table; building in a high water table could lead to flooding and structural issues.

Managing your microclimate

Even with the help of natural insulation from the earth, you’ll need to take a few extra measures to manage the temperature and humidity in your Walipini greenhouse.

To help keep temperatures steady, use insulating materials like hay bales, foam boards, or insulated panels on the above-ground parts of the structure.

And to manage humidity, install adjustable vents at the high and low points of your greenhouse to create a natural airflow. Not only will the ventilation help keep humidity in check, but it will also help cool the Walipini on hot days. If you need more help, try dehumidifiers.

Additional humidity-management strategies include water management. To prevent overwatering — which can increase humidity levels and harm your plants — check your soil to make sure it needs water before irrigating or use a moisture meter. 

Providing light for your plants

You’ll also need to put some effort into providing the plants in your Walipini with the light they need to grow and thrive. 

Orienting the Walipini’s longest side to face south will help, as we mentioned. But, in regions with less sunlight during certain seasons — or if the natural light isn’t enough for plants that need full sun, you’ll probably need to provide grow lights. If you add reflective materials to the interior walls and floor, they’ll bounce light around the greenhouse’s interior space, contributing to even more light distribution and reaching the lower parts of your plants.

If your concern is too much sunlight intensity, try using shade cloth to diffuse it and prevent plant burn, especially during the peak summer months.

Irrigation strategies

We also have some effective irrigation tips tailored for Walipini greenhouses.

One strong choice is to use drip irrigation, which delivers water directly to the root zone of each plant, minimizing evaporation and excess humidity. 

A light covering of mulch will help further reduce evaporation and keep soil moisture levels consistent.

For small Walipinis or tight areas within a larger space, try hand watering.

Final thoughts

To recap, remember:

• You’ll need a location with soil that’s stable enough to support the greenhouse structure. 
• Pick a spot that’s easy to access for construction, maintenance, and daily tasks.
• Your greenhouse should have convenient access to water and electricity, especially if you want to install irrigation or heating systems.
• Check your local zoning laws and apply for the necessary permits before construction.