Things grow wild in the tropics. The soil – often volcanic – is very fertile. Vegetation is lush and thick. There is an amazing variety of flowers and fruit.
The thing is, plants grow really wild if untended. A vacant lot left without care very quickly grows into a dense and tangled thicket – almost impenetrable. Flowering plants get choked out. Trees can be overwhelmed by vines or parasites. An army of leafcutter ants can disassemble and strip a tree, carrying off its entire foliage canopy in bite size pieces.