It is classified as an "injurious weed" under the UK Weeds Act 1959. Many weed species attract beneficial insects that improve soil qualities and forage on weed pests. Some yams are also invasive plants, often considered a "noxious weed", outside cultivated areas. It is a weed that grows in every soil. Some species can be a nuisance in shady greenhouses or a weed in gardens. The plant is federally listed as a noxious weed in many US states. Organic fertilizers such as manure are one of the best methods of weed control. It is now regarded as a noxious, invasive weed. She was also featured in Gupta's March 11, 2014, CNN documentary "Weed 2&colon; Cannabis Madness". This led to the plant being known as Jamestown weed, and later jimsonweed. In China it is seen as a noxious weed, invasive in overgrazed areas. Consequently, it is considered to be a noxious weed in many jurisdictions. Immunotherapy research suggests that treatment using "Euphorbia peplus", a common garden weed, may be effective. At home Effy arrives and talks to Freddie in his shed whilst smoking weed. Guinea hen weed and honey garlic contain a similar lachrymatory factor.