Page 26 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

Detail of the Sageretia trunk
Dormancy
As previously stated, woody temperate-climate plants require a dormant
period. This is a period of at least 42 days where temperatures are 10°C or lower.
Most deciduous trees will lose their leaves at this time whilst some others such
as Ulmus parvifolia, the Chinese Elm may remain evergreen. Evergreen species,
in particular conifers will slow their growth rate considerably.
However, tropical species do not have a dormant period as such and will
continue to grow all year round.
Air circulation and humidity

Central heating systems radically reduce humidity in our homes to near-
desert levels. All bonsai need good humidity levels to grow well indoors and
there are several ways to address this problem.
Firstly, never place your bonsai above a radiator where humidity levels are
especially poor. In general, radiators should be avoided as they also cause wild
fluctuations in temperature to their the surrounding environment.
Secondly, trees can be misted to create higher humidity levels. Misting also
cleans the leaves of dust and dirt that would otherwise collect. Don't bother

however misting religiously everyday, as excessive misting can build up salt
deposits on leaves and water runoff can result in over-wet bonsai compost. It is
far more important that the surrounding area is kept humid and this is best
provided by use of a humidity or gravel tray. This is a flat tray that holds water
into which small stones or pebbles are placed. The bonsai is placed on top of the
stones so none of the pot touches the water, as the water evaporates over the
course of 1 or 2 days it provides a continual humid atmosphere around the tree.