Yellow star-thistle is a plant that has a native range encompassing parts of the Mediterranean region but has been introduced to various continents, including Europe, Asia, and the Americas. It is sometimes thought to be a challenging species in certain areas, where its presence may have an impact on ecosystems. In some regions, yellow star-thistle is considered invasive, particularly where it has established itself across multiple ecosystems, potentially affecting native flora and fauna. The extent of cultivation for yellow star-thistle is not specified in the input.

Yellow star-thistle has spread from its native Eurasian and Mediterranean range into the Americas, the rest of Europe, Africa, and into in Asian steppes. The greatest infestations are in areas with the Mediterranean or similar climates. Yellow star-thistle is a prolific seed producer and does best in invading disturbed lands – roadsides, wastelands, and abandoned feeds. It occasionally invades crops, and also pastures, where it reduces biodiversity and the quality of the forage. Yellow star-thistle is now present in 41 US states, and officially listed as a noxious weed in 6 of them: California, Oregon, Washington, Idaho, Utah, and New Jersey. In Canada, it is found in Alberta, British Columbia, Ontario, and Saskatchewan, although it is not as persistent.

Best weeding time: Before fruition