trees and planting trees is symbolic to the cult, in fact the colors green as plant and yellow as money are also symbolic, (note the gold shovels Bill and Hillary use to plant the trees.) but to stick to plants for a moment Note the poison plants behind Obama in his six finger portrait. Or the flower under Kim Jong-il.
And the symbolism has layers often, like In that speech Q highlighted of Hillary where she mentions Super Predators and "bringing them to heel" like a DOG, and after the Oklahoma City bombing she plants DOGwood trees. She wants super predators plants. Tragedies can be used to pass legislation by manipulating the public.