bonsai general - 40 views
worth reading. I not long ago came across this paragraph in a book about maintaining trees, and I thought very succinct in describing what is happening invisibly inside the tree during times might think that is totally inactive:
cambial activity goes first in the top of the tree, then in the trunk, and finally on the roots. Therefore, a tree may also have a very active root system after visible growth or leaf fall occurred. In addition, the upper roots of the trees in the ground are the first that are active in the spring.
Makes you think, right? Another piece of the puzzle is complicating the top of the tree is much more resistant to cold than the root zone. The labels we see in the nursery containers that read ‘to_ Hardy’ is supposed to be planted in the ground where the tree roots are designed to be. Those cold ratings are only for the top; roots are tender. All a warning for those who grow bonsai. Roots are calibrated to be on the ground, not in a pot.
There are a couple of important lessons here. While light frosts in the fall alleviate a tree in latency, chilly unusually deep in the fall can kill the tree because the roots are still active. Spring is the usual time to take care of heavy frost, but the fall should be too. On the other hand, if we live in a temperate climate, with mostly rare arctic blasts to keep in mind that bonsai can not go fully dormant, preserving the active roots throughout the winter.
Healthy roots most resistant trees and shrubs are fine with light frosts in the upper mid-20s (F) part, which helps relieve them in the winter dormancy, but less than they need better protection, such as placing on the floor or in an unheated room, greenhouse or cold frame.
The bonsai who spend their winter holidays out in banks may need a careful observer of time (that would be!)
(Reference: Maintenance Tree, PP Pirone, 1988)
This article was originally published on http://crataegus.com/2012/01/17/winter-cold-and-tree-roots/