How to grow trees on a balcony. Part 2.

For the winter:
Some tender tree species can be moved inside for the winter, but many need a period of cold. A good option is to winter the tree in the garden with the container buried to the ground, if possible.
For the apartments that have no garden or a semi-cold storage space you need to choose a winterhardy tree that can be kept on the balcony. In a container the roots are vulnerable to cold and freezing, so it is good to choose a tree that is 1-2 zones more winterhardy than where you live. Cover the container for the winter with e.g. bubble wrap, also from the underside, and moved to a sheltered spot e.g. close to the wall.
The covering should be done after the tree has started it's winter dormancy, meaning after the leaves have shed, the soil has frozen a little and a longer cold period has started. During the spring the covers should not be removed too early. On warm days, start with taking the covers away first for the days only. During the cold spring nights the plant needs to be protected and covered also later. Check if the plant needs watering. The soil should not be too dry or wet, start watering more again as the growth starts again.