Fascinating article on growing citrus outside - in RUSSIA
Mar 9, 2023 9:49:28 GMT -5
pepperhead212 and Hensaplenty like this
Post by Laura_in_FL on Mar 9, 2023 9:49:28 GMT -5
I was on David the Good's site this morning and he linked to a fascinating article about growing citrus outside, in-ground, with no supplemental heat, in the former Soviet Union. And not just in mild coastal areas along the Black Sea, but in places that get as cold as 5F (-15C), and even in places where the top foot or more of the ground freezes in winter!
My first thought on reading that was, "Not possible!" But the article goes on to describe the processes they used: www.lowtechmagazine.com/2020/04/fruit-trenches-cultivating-subtropical-plants-in-freezing-temperatures.html
I recommend reading the article, because it's a really interesting read. But I will summarize a few of the methods used. (Note: in many places a combination of these methods were used.)
First, they started with cold-hardy and dwarf citrus. Then they bred for cold-hardiness, moving each generation to a slightly colder planting location.
Second, careful site selection for favorable microclimates.
Third, they pruned the trees really hard and trained them with care. Ultimately they came up with a system where the trunks were kept to only 6 inches tall - yes, you read that right - and the branches were trained to be horizontal, so that the tree essentially developed a creeping habit, forming a roughly 4-5' diameter spiderweb just barely off the ground. You might think that such tiny trees weren't productive, but reported yields were 80-200 fruits per tree, per year. The tiny trees were easy to cover, and in the warmer areas of the Soviet Union, cheesecloth and straw provided sufficient protection. As a bonus, the short stature of the tiny trees sheltered them from the worst of the hot, drying winds in summer, making them more drought-tolerant.
Fourth, in colder regions, they planted the tiny trees in trenches - details about the shape, size, and orientation of the trenches are in the article.
Fifth, where necessary, they covered the trenches in winter, usually with boards and straw, with just occasional small openings for ventilation and light. (Citrus in cold-induced dormancy need very little light.)
Sixth, in the coldest locations, they simply dug up the trees in the fall, keeping the soil around the root balls. They moved the trees into sheds for winter. (The construction of the sheds varied depending on how much cold protection the trees needed in that area.) Then each spring they just moved the trees back to their holes. Again, this was a lot easier with trees that had been kept really small by pruning and training.
There were some other tricks I didn't get into; this post is already pretty long.
Of course, these methods are all very labor-intensive. Citrus grown this way was much more expensive than imported citrus grown in the tropics. But these techniques were developed during the Soviet era, when the primary consideration was avoiding depending on other countries for food.
Maybe I will experiment with creeping citrus at my new place.
My first thought on reading that was, "Not possible!" But the article goes on to describe the processes they used: www.lowtechmagazine.com/2020/04/fruit-trenches-cultivating-subtropical-plants-in-freezing-temperatures.html
I recommend reading the article, because it's a really interesting read. But I will summarize a few of the methods used. (Note: in many places a combination of these methods were used.)
First, they started with cold-hardy and dwarf citrus. Then they bred for cold-hardiness, moving each generation to a slightly colder planting location.
Second, careful site selection for favorable microclimates.
Third, they pruned the trees really hard and trained them with care. Ultimately they came up with a system where the trunks were kept to only 6 inches tall - yes, you read that right - and the branches were trained to be horizontal, so that the tree essentially developed a creeping habit, forming a roughly 4-5' diameter spiderweb just barely off the ground. You might think that such tiny trees weren't productive, but reported yields were 80-200 fruits per tree, per year. The tiny trees were easy to cover, and in the warmer areas of the Soviet Union, cheesecloth and straw provided sufficient protection. As a bonus, the short stature of the tiny trees sheltered them from the worst of the hot, drying winds in summer, making them more drought-tolerant.
Fourth, in colder regions, they planted the tiny trees in trenches - details about the shape, size, and orientation of the trenches are in the article.
Fifth, where necessary, they covered the trenches in winter, usually with boards and straw, with just occasional small openings for ventilation and light. (Citrus in cold-induced dormancy need very little light.)
Sixth, in the coldest locations, they simply dug up the trees in the fall, keeping the soil around the root balls. They moved the trees into sheds for winter. (The construction of the sheds varied depending on how much cold protection the trees needed in that area.) Then each spring they just moved the trees back to their holes. Again, this was a lot easier with trees that had been kept really small by pruning and training.
There were some other tricks I didn't get into; this post is already pretty long.
Of course, these methods are all very labor-intensive. Citrus grown this way was much more expensive than imported citrus grown in the tropics. But these techniques were developed during the Soviet era, when the primary consideration was avoiding depending on other countries for food.
Maybe I will experiment with creeping citrus at my new place.