Nothing succeeds like succession

Annual and biennial plants typically produce a lot of seed and complete their life cycle in one or two years.  The top layer of soil is loaded with their seed.  When disturbances create openings in roadside vegetation, the seed of these opportunistic species will germinate and grow.  Thick and rank, these so-called weeds attract attention and often bring a regimen of mowing and spraying.

Before spending a bunch of money trying to kill these weeds, consider that these species are colonizing bare soil and reducing soil erosion.  As annuals and biennials, they will die after flowering.  Eliminate the source of the disturbance and these sites will be reclaimed by long-lived perennials.  If prairie grasses and wildflowers are in the vicinity, these desirable plants will move in and, after a couple years, dominate the area.

IRVM roadside managers recognize when the prudent course of action is paying a visit to the landowner responsible for the disturbance and allowing plant succession to run its course.