In December 2001 we had a record cold winter, minimum temperature -21,5°C (-6,7°F). All Trachycarpus palms were not protected. The plants of Bulgarian origin had up to 80% leaf burn, but all survived. The plants imported from Greece, Turkey and Italy all passed away. Only one Turkish palm with 2 feet of trunk survived, because it was accidentally buried under the snow. This palm lost 100% of the leaves, but developed a nice crown during the new growing season. In December 2002 , after the minimum temperatures of -14°C (6,8°F) for 4 nights, the same palm has about 50% leaf burn. For comparison, most of the Bulgarian palms have 0-5% damaged leaves, and only one has about 30% damages. On the slope 4 km away the minimum was -11,1°C (12°F). All of the palms with Bulgarian origin there look just like in summer, no damages at all.

For our experiments with other palm species and exotic plants please read the chapter Experiments from the left part of your screen.

Our state has always been very close to Russia. Well, both our nations are very close anyway, Russians use our alphabet and most of our language. It's a mistake that today we forgot "the big Russian brother", but that is another story ... Just 13 years ago we were a closed union. During the cold war Bulgarians used to have almost no access to the western countries, including Greece and Turkey. In return, we could have business or holidays wherever we want in Russia, Poland, East Germany and the other communist countries. That is why it is most probable that the palms or the seeds have been imported from the Russian's Black Sea coast. In Bulgaria the Russian Black Sea resorts are wide famous for their palms. In their scientific literature they describe palm experiments from 1820 and earlier!

During the times of Stalin in Russia to the scientists was ordered to develop subtropical fruiting and ornamental plants, able to survive the cold Russian winter at least in the southern parts of the country. Russian government wanted to show how powerful the communism is. They have made very good experiments with remarkable results. These orders were given to all of the satellite countries around USSR. Anyway, they soon realized that bananas and coconut palms will not grow there. Below are photos of a dead mandarin tree from a field on the Black Sea coast (zone 8a) in Bulgaria. Note how big the dead trunk is. This shows how big the plants have been before they died. Each plant on this citrus field was producing up to 400 fruits which were sold on the local market. About 13 years ago all experiments were stopped and the fields were left with no care at all. In a colder winter the mandarin plants have frozen and later the Poncirus trifoliata sprouted from the ground (the citrus plants have been grafted on trifoliata). All these plants have probably died in the winter of 1993. 

Now the whole citrus field produces Poncirus trifoliata fruits only.

 

In 1989 when I was a 1st year student at the Agricultural university in Plovdiv, there were 1 ha mandarin plants. They were protected each year and despite of all they died to the ground each year. Many years and much money have been spent for such researches. To be honest, most of the plants could not be acclimatized, but some were successful. It is also important that most of the unsuccessful  plants have developed much better cold hardiness. They just were not suitable for commercial production in our climate. But for private purposes they are just perfect.

And Russians ... they now have citrus trees, olives, date palms and other ornamental palms on the Black sea coast and in some colder areas, thousands of hectares. Of course, olive trees in Moscow are just a house plants.