Frequently Asked Questions A weed is designated noxious when it
is considered by a governmental agency to be injurious to public
health, agriculture, recreation, wildlife, or property. In
Idaho, noxious weed regulations are covered by Title 22, Chapter
24, Idaho Code, Noxious Weeds Law. Some general characteristics
of noxious weeds are their ability to spread rapidly, reproduce
in high numbers, and crowd out native plants. Noxious weeds also
tend to be very difficult to control. Noxious weeds can be
annuals (completing their life cycle in one growing season) or
perennials (having a life cycle spanning more than one growing
season). Most noxious weeds were originally from other
countries. Many arrived in shipments of desirable seeds, in the
ballast of sailing ships, or were introduced intentionally as
garden plants. Noxious weeds thrive in disturbed areas like
roadsides, building sites, maintenance areas, irrigation
ditches, dirt parking areas, trails, and campgrounds. Once
noxious weeds gain a foothold, they