Purple loosestrife is a beautiful perennial plant that has a dark side. It has the ability to invade natural wetlands and displace native plants such as cattails and sedges. It also affects agriculture by becoming a nuisance in moist rangelands and in crops planted in flood plains. Some states have passed legislation officially designating purple loosestrife (Lythrum salicaria) as a noxious weed, and thus restricting its sale and distribution.
Imagine a horror movie depicting a plant species that grows everywhere, consuming cars, buildings, and everything in its path. Although this is strictly science fiction, there are plants that are quite aggressive, taking over a garden, forest, or turfgrass areas in a short period of time. An example of this is the kudzu vine (Pueraria lobata). It was widely grown in the southeast United States as a fodder plant, to control erosion, and sometimes as an ornamental. Due to its rapid growth rate it has become a rampant weed. Fortunately, kudzu is not hardy in Iowa.