This article discusses constructing a simple Walipini greenhouse. The idea with citrus is to maintain above freezing temperatures year around. The right citrus is step 1 and the right greenhouse is step 2.
A Walipini greenhouse is an innovative way to grow fresh food year-round, even in colder climates. This underground greenhouse uses the earth’s natural insulation and passive solar energy to maintain warm temperatures, reducing energy costs and extending your growing season. Here’s a detailed guide to help you build your own Walipini, from planning to planting.
1. Understand the Walipini Concept
The term Walipini comes from the Aymara language, meaning “place of warmth.” It’s essentially an underground greenhouse designed to harness the earth’s thermal mass and solar heat. By being partially or fully buried, the Walipini maintains a stable temperature, protecting plants from freezing temperatures during winter.
Unlike traditional greenhouses, a Walipini requires minimal external energy input, relying on smart design principles to capture and retain heat. This makes it an eco-friendly, sustainable option for gardeners in cold or variable climates.
2. Choose the Right Location
Selecting the best location is critical to your Walipini’s success. Ideally, choose a site with maximum sun exposure throughout the day.
In the northern hemisphere, a south-facing slope is best.
In the southern hemisphere, face your Walipini north.
Avoid areas prone to flooding or poor drainage.
A slightly elevated spot with natural drainage is preferred to prevent water buildup.
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Access to water and proximity to your home or garden will also make maintenance easier.
3. Plan the Dimensions
Before you start digging, determine the size of your Walipini based on your available space and needs.
A common size is about 6 feet (1.8 meters) deep, 20–25 feet (6–7.5 meters) long, and 8–12 feet (2.5–3.5 meters) wide.
The north wall should be taller than the south wall (in the northern hemisphere) so the roof can tilt toward the sun at an optimal angle for light and heat capture.
Sketch out your plans carefully to ensure correct angles and proportions.
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4. Dig the Pit
Excavation is the most labor-intensive part.
Dig the ground to the planned depth and dimensions.
Slope the floor slightly toward a drainage system—such as a gravel trench or drain pipe—to manage water and prevent flooding inside the greenhouse.
Consider renting machinery if the pit is large or soil is tough to dig.
5. Install Drainage and Insulation
Proper drainage and insulation are essential to keep your Walipini dry [Upload failed]nd warm.
Add a thick layer of gravel or crushed stone at the bottom of the pit to facilitate water drainage.
Insulate the walls by stacking straw bales, foam board, or earthbags against the pit’s sides to retain heat. Straw bales are natural, affordable, and effective.
These measures protect your plants from cold drafts and moisture.
6. Build the Structure
The Walipini’s frame and roof keep everything secure and maximize sunlight.
Use durable materials such as treated wood, metal framing, or repurposed materials for the frame.
Construct a roof that tilts toward the sun, covered with transparent materials like polycarbonate panels or greenhouse plastic sheeting. These allow sunlight in while keeping heat trapped inside.
Ensure the structure is strong enough to support snow loads if you live in a snowy region.
7. Add Ventilation and Access
Good ventilation prevents overheating and controls humidity.
Install vents or operable windows near the roof to release excess heat during warm days.
Build a well-insulated doorway or hatch for easy access, ensuring it seals tightly to maintain warmth during cold weather.
Automated vent openers can be a great addition for hands-off climate control.
8. Optional: Add Thermal Mass
Thermal mass materials absorb heat during the day and release it slowly at night, stabilizing temperature fluctuations.
Place barrels filled with water, large stones, or bricks inside the Walipini.
These elements act like natural heaters, helping to keep the environment cozy overnight.
Position them where they will get direct sunlight for maximum effect.
9. Prepare the Growing Beds
Now, create comfortable growing areas for your plants.
Build raised beds or plant directly in the ground, depending on your soil quality and preference.
Enrich the soil with plenty of compost and organic matter to boost fertility and drainage.
Raised beds can improve soil warmth and drainage, which is helpful in cooler conditions.
10. Start Planting
Choose crops suited to the season and environment inside your Walipini.
For winter, plant cold-hardy vegetables such as spinach, kale, carrots, and lettuces.
During warmer months, grow tomatoes, peppers, cucumbers, and herbs.
Keep an eye on temperature and humidity levels to maintain ideal growing conditions.
Harvest fresh produce all year long!
Benefits of a Walipini Greenhouse
Building a Walipini comes with many advantages:
Year-Round Growing: Extend your growing season well into winter, even in cold climates.
Low Energy Use: Relies on passive solar heating, eliminating the need for costly heating systems.
Cost-Effective: Uses natural materials and earth insulation, reducing construction and operating costs.
Weather Protection: Shields plants from frost, wind, and pests.
Sustainability: Supports eco-friendly gardening with minimal carbon footprint.
Final Tips
Starting a Walipini requires planning and some hard work upfront, but the rewards are well worth it. Make sure to monitor soil moisture regularly, and adjust ventilation to keep your plants healthy.
If you’re looking for a sustainable way to grow fresh food all year without relying on electricity or gas heating, a Walipini greenhouse is an excellent solution. It connects you with nature’s rhythms while providing fresh, homegrown produce in any season
I have wondered about doing something like that and put a greenhouse roof on top of our old trench silo that is 10’ deep (I figured it could probably stay fairly over 0°f even on the coldest of nights, without heating, which would enable the most cold hardy hybrid citrus, figs, and pomegranates.
But the biggest concerns for me would be; how to make a simple way to ventilate it in the summer to prevent everything from toasting, 3’ of wet snow can weigh a lot, and it would be a lot of work to water (unless a pipeline was put to it).
I have a plan for that. I’m going to run underground corrugated piping. The way that works is 8’ underground is a constant 50 degrees most of the year. The plants will be getting air from the ground year round. The fans will push or pull greenhouse air into the ground through the corrugated pipes. A normal greenhouse has an R factor of 1 which is challenging to regulate temperatures. By putting a greenhouse in the ground the dirt walls hold heat and cold to radiate at night or during the day. The earth is like a giant battery that stores temperatures for us. I’m not saying I won’t have challenges because I’m sure I will. I’m counting on the use of cold hardy citrus giving me a very big edge. Things like yuzu are very hardy. The Thomasville Citrangequat Tree is very cold hardy also.
“Thomasville citrangequat is a complex hybrid involving a citrange (Sweet orange x Trifoliate orange) and a kumquat. It was developed by the United States Department of Agriculture in the early 20th century as an attempt to combine the hardiness of the citrange with the delayed dormancy of a kumquat. It was named for Thomasville, GA, where it first fruited. Several different citranges were developed, but of these, Thomasville is the most widely grown and best tasting. Thomasville citrangequat makes a small tree to 15-20 feet. Juvenile leaves are frequently Trifoliate, but mature plants produce unifoliate leaves. Like its kumquat parent, Thomasville citrangequat is a repeat bloomer, and mature plants will frequently produce two (or more) crops in a single season. The fruit are the shape and size of a hen’s egg. They turn yellow in late fall. Left on the tree, the fruit eventually turn bright orange. Although it does not have commercial potential, Thomasville citrangequat makes prodigious crops of fruit that have a variety of home uses. Due to its kumquat ancestry, the entire fruit can be used, peel and all. In late summer, when the fruit are still green, Thomasville citrangequat fruit can be used as a lime. In fall, the fruit can be used as a lemon or used to make an excellent marmalade. Left on the tree, the fruit becomes edible out of hand by late winter, tasting like a common sweet orange. Thomasville citrangequat is an excellent cold-hardy citrus for anyone who wants to grow highly ornamental, useful fruit with very little effort.
Mature Tree Height: 15-20 feet
Ripens: Fall/Winter
Hardiness: 5F *
Tastes Like: Lemon/Lime early to Sweet Orange later in season”
Fruit Trenches: Cultivating Subtropical Plants in Freezing Temperatures
During the first half of the twentieth century, Soviet citrologists grew (sub)tropical plants in temperatures as low as minus 30 degrees Celsius – outdoors, and without the use of glass or any fossil fuel-powered assistance.
Citrus fruits (oranges, lemons, mandarins, tangerines, grapefruits, limes, pomeloes) are the highest-value fruit crop in terms of international trade. Citrus plants are not frost-hardy and can only be grown in tropical and subtropical climates – unless they are cultivated in fossil fuel heated glasshouses. However, during the first half of the twentieth century, citrus fruits came to be grown a good distance from the (sub)tropical regions they usually thrive in. The Soviets managed to grow citrus outdoors, where temperatures drop as low as minus 30 degrees Celsius, and without the use of glass or fossil fuels. By 1950, the Soviet Union boasted 30,000 hectares of citrus plantations, producing 200,000 tonnes of fruits per year.
The Expansion of Citrus Production in the Soviet Union
Before the first World War, the total area occupied by citrus plantations in the Soviet Empire was estimated at a mere 160 hectares, located almost entirely in the coastal area of Western Georgia. This region enjoys a relatively mild winter climate because of its proximity to the Black Sea and the Caucasus Mountain range – which protects it against cold winter winds coming from the Russian plains and Western Siberia.
Nevertheless, such a climate is far from ideal for citrus production: although the average winter temperature is above zero, thermal minima may drop to between -8 to -12 degrees Celsius. Frost is deadly to citrus plants, even a short blast. For example, at the end of the 19th century, the extensive citrus industry in Florida (US) was almost completely destroyed when temperatures dropped briefly to between -3 and -8 degrees Celsius.
From the 1920s onwards, the Soviets extended the area of citrus cultivation to regions considered even less suited. Initially, citrus production extended westward along the Black Sea coast, a region unprotected by mountains, and where temperatures can drop to -15 degrees Celsius. This includes Sochi – which hosted the 2014 Winter Olympics – and the southern coast of Crimea. At the same time, citrus cultivation extended eastward to the west coast of the Caspian Sea, in Azerbaijan.
Citrus production was then spread to regions where winter temperatures can drop to -20 degrees Celsius, and where the ground can freeze to a depth of 20-30 cm: larger parts of the earlier mentioned zones, as well as Dagestan, Turkmenistan, Tajikistan, Uzbekistan, and the southern districts of Ukraine and Moldova. Finally, citrus cultivation was pushed further north in these regions, where winter temperatures can plummet to -30 degrees Celsius, and where the ground can freeze to a depth of 50 cm.
Frost was not the only obstacle to citrus cultivation in these parts of the world. The region is also characterised by excessive summer heat and strong, dry winds.
From Import Dependency to Self-Sufficiency
Before the first World War, almost all citrus fruits in ancient Russia came from abroad. The main suppliers were Sicily (for lemons) and Palestine (for oranges). Some 20,000 to 30,000 tonnes of citrus fruits were imported annually. Its consumption with tea, the national drink in Russia, meant lemon made up almost three-quarters of these imports.
In 1925, following the Russian Revolution and the civil war, citrus growing became the subject of planned development. The Communist Party was determined to become self-sufficient in citrus production, and no efforts were spared. They set up several research establishments and nurseries, as well as test fields in more than 50 locations.
By 1940, the acreage had grown to 17,000 hectares and production reached 40,000 tonnes, double the annual imports under the old regime. By 1950, the area planted with citrus fruits reached 30,000 hectares (56% mandarin trees, 28% lemon trees, 16% orange trees), and production grew to 200,000 tonnes of fruits per year.
The large share of mandarin trees can be explained by the fact that they are the most cold-resistant of all citrus fruits, tolerating frosts to about -2 degrees Celsius. Lemon trees, on the other hand, are the least cold-resistant citrus variety.
There are three reasons why the Soviets managed to grow citrus fruits in regions that were (and are) considered totally unfit for it. First, they bred citrus varieties that were more resistant to cold. Second, they pruned citrus plants in radical ways that made them more resistant to cold, heat and wind. This eventually resulted in creeping citrus plants, which were only 25 cm tall. Third, they planted citrus plants in unlikely locations, most notably in trenches of up to two metres deep.
“Progressive cold-hardening”
Imported citrus varieties only survived in a few isolated points along the Black Sea coast, which enjoyed a particularly favourable microclimate. To better prepare citrus fruits for cold, Soviet citrologists followed a method called “progressive cold-hardening”. It allowed them to create new varieties which were adapted to local ecological conditions, a cultivation strategy which had originally been developed for apricot trees and grapes.
The method consists of planting a seed of a highly valued tree a bit further north of its original location, and then waiting for it to give seeds. Those seeds are then planted a bit further north, and with the process repeated further, slowly but steadily pushing the citrus variety towards less hospitable climates. Using this method, apricot trees from Rostov could eventually be grown in Mitchurinsk, 650 km further up north, where they developed apricot seeds that were adapted to the local climate. On the other hand, directly planting the seed of the Rostov apricot tree in Mitchurinsk proved unsuccessful.
The method, developed following the observation that young plants started from seed adapt to the conditions of the new environment, also proved successful for citrus fruits – which retained high yields and high quality fruits. As well as “progressive cold-hardening”, from 1929 onwards the Soviet citrologists performed a methodological selection of cold-resistant varieties, which were hybridised with the best local varieties. This was facilitated by an extensive collection of citrus fruits, which included almost all representatives of the genus Citrus.
Dwarf and Semi-Dwarf Citrus Trees
In the main citrus growing centres worldwide, pruning citrus plants was very rare. Harold Hume, a renowned Canadian-American botanist, even advised to “keep pruning shears as far as possible from the citrus plantation”.
However, pruning was crucial to the cultivation of citrus plants in the Soviet region. First and foremost, pruning reduced the height of the citrus plants. Conventional lemon trees grow up to 5 metres tall, while orange trees can be 12 metres tall. On the other hand, even prior to the 1920s, Soviets worked with dwarf and semi-dwarf citrus trees, which were only 1 to 2 metres tall. These trees were further pruned to have compact crowns.
More compact trees have two advantages. First, closer to the ground, temperature variations are smaller and wind speed is lower. Second, smaller trees are easier to protect against the elements. In the region with the mildest climate, where an initial 160 ha of citrus fruits were grown, plantations were often located on terraces or on steep slopes, taking up the smallest piece of land with a favourable microclimate.
Image: “Collecting tangerines at the Chakva state farm”, a painting by Mikhail Beringov, 1930s.
During winter, individual citrus plants in these plantations were protected by a shelter made of cheesecloth or straw mats, supported by a light frame of poles. Plantations were also surrounded by windbreak curtains, arranged in such a way that they mitigated both the cold winter winds and hot, dry summer winds. These curtains also channeled the cold air masses descending from the tops of the hills outside of the plantations.
Further protection against cold and wind was generated by planting trees very close together – up to 3,000 plants per hectare. Excessive summer heat was counteracted by spraying whitewash on the upper part of the leaves, which lowered their temperature by about 4 degrees Celsius. All these methods work for large-stemmed citrus trees, but of course they are much cheaper and easier to perform on trees with a height of only 1 to 2 metres.
Creeping Citrus Trees
Training small citrus plants was key to extending their cultivation across all regions of the Black Sea coast, where until then it had been impossible. This was achieved by pruning and guiding citrus plants into a creeping form, which reduced their height to a mere 25 cm.
The crown of creeping citrus plants was formed in two ways. In the first method, the trunk of the tree took an inclined position as soon as it left the soil. The main branches of the crown, formed in a unilateral fan, touched the ground, and so did the fruits. In the second method, the 10-15 cm tall stem was kept straight while the main branches developed radially at an angle of 90 degrees to the trunk, thus (seen from above) forming a spider-like crown. In this case, the branches and the fruits did not touch the ground, and this proved to be the most successful method.
Image: Creeping culture, here applied to an apple tree. Source.
Creeping citrus trees offered even better protection against cold and wind compared to dwarf and semi-dwarf trees, because the creeping crown created a microclimate that softened both the summer maxima and the winter minima. During a 10-year long test, it was found that in winter, the air layer at the level of the creeping crown was on average 2.5 to 3 degrees Celsius warmer than the air layer at 2 metres above the ground. In summer, during hot weather, the difference in temperature could exceed 20 degrees Celsius.
Wind protection was just as effective. The wind speed at 2 metres above the ground reached an average of 10.4 metres per second, while it was only 1.8 metres per second at the level of creeping lemon trees. This limited dehydration of the crown so that less water was needed.
Logically, the very small size of creeping plants made it even easier and cheaper to protect them against the elements. Moreover, as a protection strategy it proved to be more effective: during the winter of 1942-43, when temperatures along the Black Sea coast went down to -15 degrees, creeping lemon trees protected by a double layer of cheesecloth and by windbreaks did not suffer in any way, while similarly protected taller-stemmed lemon trees froze to the roots.
Perhaps surprisingly, creeping citrus plants had higher yields than semi-dwarf citrus plants. The fruits ripened earlier, and produced more fruits, especially during the first years.
Cultivating Citrus Trees in Trenches
None of the above mentioned cultivation methods were sufficient to grow citrus fruits in regions where the ground froze and where winter temperatures dropped below -15 degrees. Here, citrus plants were cultivated in trenches. Obviously, growing citrus fruits in trenches was only practical with dwarf and – most often – creeping plants. In this method, soil heat protects citrus fruits from frost.
The depth of the trenches varied from 0.8 to 2 metres depending on the winter temperature, the depth to which the ground froze, and the water table. The trees could be planted in single or double rows. Trenches were generally trapezoidal in section to improve light conditions. They were roughly 2.5 metres wide at the bottom and 3 metres wide at the top for single rows of plants, and 3.5 metres wide at the bottom and 4 metres wide at the top for double rows of plants.
Image: Cultivating citrus trees in trenches. Kolhoz Stalin, agricultural area around city of Tashkent.
If necessary, the walls were coated with clay or reinforced with brick or shell rock. Inside the trench, the plants were positioned 1.5 metres apart from each other, and when two rows were planted, each plant in the first row was located between two plants in the second row. The length of the trenches depended on the nature of the terrain, but did not surpass 50 metres.
Trenches were located on level ground or light slopes, oriented from east to west in order for optimal sunlight during the winter months. They were spaced apart 3-5 metres from each other when they contained a single row of plants, and 4-6 metres when they had a double row of plants. Trenches could be connected to each other, which made it more convenient to care for the plants.
The space in between the trenches allowed for the placing of shade screens or planting of natural shading plants. These increased the humidity in the trenches and protected the citrus plants from overheating in summer.
Covering the Trenches
During the summer, plants received the same care as those planted in the ground under “ordinary” conditions. When winter came, the trenches were covered with 2 cm thick wooden boards and single or double straw mats, depending on the climate. This kept the soil heat in the trench, while keeping precipitation out. If a layer of snow covered the boards, it was left in place for extra insulation. The boards were sloped at an angle of 30-35 degrees. When in winter the temperature rose above zero degrees Celsius, the cover was raised on the south side or completely removed during the day.
This method cannot be applied to any plant. Citrus plants tolerate very low light levels for 3-4 months per year, provided that the temperature of the air in contact with the crown is maintained between 1 and 4 degrees Celsius. At this temperature, the metabolism of the plants weakens, which improves their resistance to cold.
Glass was only used sparingly. Wooden boards gave much better frost protection, were much cheaper, and could be made from local materials. The plants needed some stray light, so that up to a quarter of the trench shelter area was made of glass frames, which were covered with straw mats as well as a top cover of earth and clay. Only a few openings here and there provided light and ventilation.
The cultivation of creeping citrus plants in trenches, although labour-intensive, was a simple method that did not require large investment, and provided high yields (80 to 200 fruits per stem per year) as well as high quality tropical fruits. All types of citrus fruits were grown in trenches.
Other Cultivation Methods
Apart from trenches, Soviet citrologists used other types of shelters to grow citrus plants – all of which were more effective with smaller sized trees (usually dwarf cultures). Some included (usually sparse) use of fossil fuels.
A first example is the cultivation of citrus fruits with annual transplantation. Citrus plants spent the summer outdoors, but as winter approached, they were dug up with the clod of earth surrounding their roots, and transported to wintering sheds, where they were crammed together for as long as it was freezing outside. In spring, they were moved back to their original location. Where the winters were relatively mild, these winter sheds were light wooden buildings that were generally unheated. In colder regions, they were made of masonry, half buried into the ground, and fitted with heating devices.
Citrus plants were also grown in unheated glasshouses. These “limonaria”, located on the Black Sea coast, were semi-circular glasshouses, built around particularly well-exposed hills with terraces. The trees were grown as espaliers – a method reminiscent of the fruit walls in northern European countries, which facilitated cultivation of peaches and other Mediterranean fruits at high latitudes.
Heated glasshouses, which used electric heating and artificially controlled carbon dioxide and humidity throughout the year, were only used in industrial centers located beyond the Arctic Cycle. Finally, citrus fruits were grown throughout the Soviet Union in pots or boxes in apartments, schools, public buildings, and even in the glass halls of factories and workshops – making use of the waste heat from space heating or industrial processes (steam or hot water).
Few of these methods would have been profitable under a free trade regime. Considerable research investment went into kickstarting domestic citrus production. Although most methods did not require fossil fuels and were possible using cheap and locally available materials, they were very labour intensive. Domestic citrus production was only possible because it was sheltered – not only from frost, but from foreign competition too.
М. А. КАПЦИНЕЛЬ, ВЫРАЩИВАНИЕ ЦИТРУСОВЫХ КУЛЬТУР В РОСТОВСКОЙ ОБЛАСТИ РОСТОВСКОЕ КНИЖНОЕ ИЗДАТЕЛЬСТВО Ростов-на-Дону —1953. (“Growing citrus cultures in the Rostov region”, M.A. Kaptsinel). http://homecitrus.ru/books.html
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25 Reactions
Sean O’Brien
Fascinating article, but I did have a couple questions.
What are some of the disadvantages of smaller trees? I would assume that tightly-pruned crowns would make it harder for the fruits to grow. How were pests kept away from the ground-creeping varieties? How were the fruits kept off of the wet ground?
Jude
I imagine a great deal of rain pooling at the bottom of the trenches during summer rains. Wouldn’t this kill the trees?
Ron
Fantastic article. It has left me wondering about soil types in the areas where these technologies were successfully implemented.
Soils in trenches must have been free draining at the very least.
Oliver Drerup
I am very interested in Russian horticulture and want to thank you for making this valuable information available.
I have worked in residential construction in Russia (Tver Region) and was struck by the horticultural practice and plant selection employed by the Transport and Highway Departments in the Region. It appears to me that the plant material and maintenance regime required to sustain safe and attractive highway verges and medians is much better thought through in Russia than where I make my home in Ontario, Canada. Russia seems to rely less on chemical interventions and the byways look better and requires less investment.
I want to encourage you to research this aspect of Russian horticulture and share what they know with the world. Roadway planting is a major expense and should be much better designed for low intensity maintenance, particularly in colder climates. I have attempted to research this area a bit and find good information difficult to locate. Many thanks for your consideration of this issue and thank you again for your excellent work.
Graham Ford
Another brilliant article, Kris. Thank you!
Tom
I wonder if this could be used for other plants like peppers which can die off if the temperature goes below 50 Deg F.? This does almost sound like a larger version of a Walipini
George Kabourakis
Very interesting! I am wondering if some of those practices, mainly the trenches’ agriculture could have an implementation as protected agriculture for hot arid climate as it is considered to be the case in mediterranean/south european countries because of climate change. If there are thoughts/ information about that it would be interesting to read them.
Tara
Oliver, I’m interested in roadside planting. Here in NYS, there is heavy use of RoundUp and tractor mowing. What is better?
Still has to be filed under not practical or useful information though it is fascinating. The article about using stone walls in Europe was more useful. I read the sci-fi series 1632 and am always looking for things like this.
joel LeGrand
I know a Lady who had a square pit greenhouse for house plants in 1965. I am looking into using the method in your article in zone 8 for citrus,pineapple,banana & maybe nightshade plants, if there is enough room. Great article! Thanks.
vicente luis cucala
Gracias por este trabajo de investigación.
A lo largo y ancho del mundo se encuentran cultivos sorprendentes, que solo son posibles a la necesidad o la obstinación humana.
En las isla de Lanzarote, España, es posible el cultivo de la vid y de otros cultivos a pozas o defensas y las practicas que se aplican.
Atentamente.
Vicente Cucala
Josh S.
Great article!
Dave Bross
This may be VERY important info in the near future. We’re headed into a Grand Solar Minimum, an event every 400 years that leads to much colder climate everywhere for a while.
For those not familiar, Curtis Stone is a young Canadian market gardener who has been very generous with all the info that made his operation work well, and most of it is up on Youtube. Here’s his video looking into what’s coming weather-wise:
Also….many thanks for this article. Excellent work!
kervennic
Concerning the selection for cold hardiness and Lyssenko, there is a guy in France, Poots, that tried and succeeded in selecting tomatoes and many other vegetables to drought.
I am using his seeds and they do work (I cultivated leek without any watering after plantation during the driest summer ever reoorded here.
I think you can explain the fact that he succeded by selection of certain characters (there is a great variety of them in the seeds we buy if they are not hybrid). He was carefull to start from old varieties, some of them coming from St petersburg depository. But another explanation is epigenetics and that is something that was not known a few decades ago.
I’m from the former Soviet Union. And I’d like to say that more than half of tech info in soviet magazines, newspapers, and books had a very small relation to reality. I never saw a grapefruit till 90th. Inventors got their patents and even got some money for inventions, but most of that inventions were buried in tables of bureaucrats. Because from Stalin’s times we knew very clearly: Western goods are better and we should copy-paste it, as Chinese do nowadays.
MK KIm
I wish I could buy the dwarf citrus seeds robust to cold area
Brian
Can you grow winter vegetables in climates that are too cold in winter for it using these methods?
Michael Saalfeld
Some ten years ago I came across reports that similar methods for growing citrus were used in Hungary in the communist era. I wrote about this in an old citrus growers forum post which I called ‘The Communist Oranges of Hungary. Still available at http://citrusgrowersstatic.chez.com/web/viewtopic7897.php
The pictures were adapted from a publication in Hungarian shown at
Apparently ‘Magyar narancs’ (Hungarian Oranges) is still used in Hungary as an expression meaning ‘an impossible task’ or ‘a stupid enterprise which will doubtless fail’!
Grant Scarboro
Perhaps this can be used in western countries to grow oil palms? If so, a lot of deforestation might be prevented.
I have a question about this way to cultivate citrus plants:
-how do they deal with rainwater, because i can imagine that in Switzerland for example where there is sometimes lots of rain, the tranches could simply get full of whater, or be to humid for the trees….
Thanks a lot for this very inspiring article and I would be happy to hear from you,
léo
Anonymous
I’d like to observe that Michurinsk isn’t anywhere near the cultivation regions shown on the supplied map. None of the photographic evidence provided by this article points to successful citrus cultivation that far north. Odessa and New Athos are on the Black Sea coast, Tashkent is inland at a similar latitude, mean average temperatures there are apparently only just below freezing.
The paper supplied notes that Soviet citrus production was not, in fact, meeting demand, contrary to what the headings imply. I suspect you’ve been duped by the Soviet Union’s tendency to exaggerate its successes, and downplay its failures.
Kris De Decker
solar [at] lowtechmagazine [dot] com
“
This concept takes some research but ofcourse the best teacher we know is experience. We can benefit from the mistakes and success others have had.
Traditional greenhouses don’t work that well. The Amish and others know that because within an hour of the sun going down the inside temps of the greenhouse in a traditional greenhouse are the same as the outside temperature. That is not true of a hole in the ground. As a small child the world used glass a lot and had no trash service as we know it now. As a result in the winter I would see an old jelly jar turned over and packed down in mud in the winter with green grass growing inside the jar. It reminded me of spring coming but it was the dead of winter. I understood what i was seeing was because temps low to the ground are warm from dirt. The glass allowed the dirt to warm all day which was sufficient to keep grass green all winter inside that jar.
I would question the plans for building a Walipini GH. Insulate the walls and then add thermal mass? That’s not the plan at all. The earth is the thermal mass and the heat source. Why would you insulate it? That makes me question any of the advice.
Many people explain the insulation techniques and reasons poorly. The way it works is in very cold places it is better to lay concrete insulation 10 feet down then install line and fill over the lines and insulation with sand. That only applies to places like Canada , Alaska, Russia etc. That is because it’s not 50 degrees down 8’ like it is here. That was not explained here at all. The info is always poor but the concept is valid. I agree “The earth is the thermal mass and the heat source” . The sun heats the soil and the earth is our heat source at night. I would run additional lines out into the field to push more heat into the ground and pull more cold from the ground when I needed both. In the summer we need it cooler and the earth has that. In the winter we need heat and the earth has that but we need a fan to pull and push the temperature controlled air around.
Some highlights from the article that I would like to draw particular attention to:
That last quote with which the article closes does not dissuade me from consideration. Most of us do not grow fruit trees because we expect to save money on the end product but instead for our own particular differing reasons.
I’m glad you picked those things out. That clever trick about growing the entire plant inches from the ground in very cold climates was ingenious. That is true zone stretching. They knew there was more heat inches off the ground than higher up on the tree due to the warmth from the ground. Notice the prague in this video. That is a good indicator it wants more heat than zone 7. Clearly it’s a great video and the guy did a nice job growing those trees. His swingle was loaded!
i wonder how this affects the moisture level of the ground. my understanding is citrus needs a lot less water than like annual vegetables (or at least mine seems to at the size it is) and it being lower seems like it would get a lot more water. here id have to worry about flooding if i dug down like that i think.
You are right , and the moisture is your enemy as you know with citrus. That means corrugated drain pipe throughout and a slope is a must. I plan to run my 4” pipe down a hill. You can run heat through that same series of pipes if you want. That could be heat coming up through the floor etc. You could close off that pipe part of the time if you wanted to. We know a system like this works because it’s proven
I have heard Russ passed away. Many of us are thankful for his contributions to cold hardy citrus knowledge.
I have a neighbor with a Walpini and theirs is much more like a high tunnel than a greenhouse. It has removable greenhouse plastic top and only one side is buried, the other is not. They have a typical looking high tunnel fan but no heater. I would think it freezes in theirs- even with the thermal mass of the earth wall, since the plastic can only do so much to keep heat in and we have some pretty long, low temps.
However it is a huge extension to the growing season and allows for a very early start. Apparently, the walpini allows for even earlier starts than the typical high tunnel.
Their soil is like mine and drains very fast and very well. If it didn’t, I can imagine this being a big problem.
The people who’ve made theirs with geothermal heat are pretty cool - but that’s whole order of magnitude more expensive.
There’s also been a bunch of university projects with passive solar greenhouses that are worth looking at.
I’ve started on my “deep winter” greenhouse. If I were to make it 10 feet deep, the plants wouldn’t see sunshine all winter, the angle of the sun is too low. I’m doing 2’ drop (i.e. you’ll have to step 2’ down to get inside) 4’ climate battery below that. Thats a lot of excavation for my 18” backhoe bucket.
Won’t the determination of excessive depend on climate and objectives for the crops of interest. 10 ft deep would certainly be excessive in my new zone 8b/9a for citrus, But it might not be adequate for citrus in 4a. In KS maybe a bit overboard. Just my opinion. No expert on these. It depends on what else is done.
Yes , 10’ is excessive even here in 6A. Maybe in a different climate it is needed. I’m doing 2 layers of plastic as well. The hard plastic is not cheap but that is the way i went on the outside skin of the top.
I spent a lot of time on the sun angles and snow concerns. At the peak of winter 10ft wall would have the sun hit the ground at ~27ft back. (in Mercer WI zone 4a). Frost depth is 5ft. Snow provides a lot of insulation but in my conditions I’d be better off planting in a root cellar with removable roof and wall… I say this with no practical knowledge or first hand experience. Just an Excel spread sheet and a lot of geometry calcs.
A couple of things will help you with light. It doesn’t have to be direct light on your plants. Use a covering like Palring 175 that diffuses the light. And make everything possible inside the GH reflective. Bounce the light around and some will hit your plants.
What crops are you wanting to grow in your structure? Citrus will be a lot more demanding than deciduous fruits like say peaches. Peaches can easily drop to zero for several months and don’t need light in winter. Whereas citrus needs at least 20F warmer.
The other thing to think about is retractable insulation over the glazing at night and during really cold spells. That’s what the Chinese do. It saves a huge amount of heat. Way more than you will gain from the ground climate battery setup.
Why didn’t i think of that! You put an insulation blanket on the greenhouse panels at night! That’s ingenious and I read that nowhere but from you! You are one of the people i really rely on to have some good tips like that.
