The extensive root system with waxy leaves make it hard to control. It is an aggressive perennial. There are no natural enemies of the toadflaxes here in the US, so they tend to spread quickly. The following weeds have not been declared noxious, but are troublesome. A perennial in the mustard family commonly found in riparian areas, this plant has deep-seated rootstocks that make it difficult to control.
Hoary cress is a deep-rooted perennial also in the mustard family.
All other photos courtesy of the Western Society of Weed Science.