2. Avoid the existence of dead branches: The elm is to restrain Yin Qi, and dead branches are one of the sources of Yin Qi, so it is necessary to avoid dead branches on the elm, otherwise it will affect the elm's exorcism.
3. Avoid skew of elm: Elm is a feng shui tree species. In home feng shui, elm is not skewed, otherwise it will easily lead to the shift of home feng shui center of gravity.