How to Grow and Care for Thistles

Bull thistle (Cirsium vulgare) is a thistle plant native to Europe, Africa, and Asia. Bull thistle produces a large amount of nectar and attracts pollinators. Bull thistle is considered a noxious weed in areas of Europe and Australia.

This aggressive weed spreads across grasslands and fields via underground roots that creep horizontally, some for more than 5 m. It can cause major problems to agriculture if its growth is left unchecked. Its seeds feed many birds as well as pest insects. Creeping thistle is generally considered a noxious weed even in its native territory.

Texas thistle (Cirsium texanum) is a plant species that attracts the painted lady butterfly. In addition, goldfinches love to eat texas thistle seeds and the silky material that surrounds the seeds. This plant's flowers look like miniature pom-poms and can be either pink or lavender.

Bull yellow thistle (*Cirsium horridulum*) is a flowering plant related to the sunflower that is native to North America. Bull yellow thistle is also referred to as the Horrible Thistle, the Spiny Thistle, and the "Big spine Thistle." Thomas Nuttall, an English botanist who worked in America, called the plant "terribly armed."

The stem height is 49 to 91 cm. The leaves cleave like feathers and have thorns on the edges. The base of the foliage holds the stem. Root leaves remain during the flowering season. The flowering season is from spring to summer, and some japanese thistle have the characteristics of spring blooming but rarely bloom until fall. The flower (head-like inflorescence) is composed only of cylindrical flowers, and the diameter is 4 to 5 cm. The flower is typically purple, but can rarely be white.