[1] Hundreds of large trees are topped each year, which causes significant stress and future safety issues.
If a large tree is unable to produce enough sugars to feed the roots, it will slowly die from starvation.
Firstly, this adventitious growth is succulent and susceptible to attacks by insects such as aphids and caterpillars, and pathogens like fire blight (Rosaceae).
A tree may be blocking the mountain view, shading the garden, or interfering with solar energy collection.
[5] Large pruning wounds, such as those left behind in trees after topping, may become entry points for pathogens and may result in extensive decay.
These new multiple leaders are less well-attached than was the original treetop, partly due to the effect of advancing decay at the wound site.
Other cultural practices include choosing plant material that will fit in the desired location at its mature size.