It's almost impossible to misidentify a thistle. If interested in participating in a biocontrol program for this thistle, please contact our office. The plants are 1-3′ tall, and leaves attach in an alternating pattern up the stem. The breathtaking globe-shaped purple flowers are loved by many, but the seeds they produce can survive in the soil for up to 20 years. north-east United States (zones 4-7), but do grow elsewhere. Seeds are viable in the soil for up to 20 years. Typical leaf length is 3-4″ inches, although they may reach up to 8″ long and 1″ wide. At this stage, the herbicide can move downward with food reserves to the roots, thus killing the entire plant. One of the easy-to-spot botanical differences between thistles and their numerous relatives in the daisy family, is that the overlapping bracts (involucre) found directly below the flowers of thistles, are always spiny. is informational in nature. Canada thistle develops seed sparingly and may produce 1,000 to 1,500 seeds per flowering shoot. Once in bloom it is easily identified as a thistle. No single practice will result in thistle-free pastures. Typically the flowers are pinkish to lilac, but some flowers can be almost white. Identification (see below for more photos) Branching, erect biennial, 2 to 6 feet tall Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. The petals are ray florets and they have a sweet vanilla scent. While we strive to be 100% accurate, it is solely up to the reader to ensure proper plant identification. There are several biological control agents available to release on Canada thistle. From the Fields - Can Spring Forage Stands Still be Seeded? The Canada thistle flowers June to late September in the northern hemisphere. Mowing at this stage (before flowers open) will help reduce seed production. Managing Natural Grazing Behavior for Impoved Pasture Productivity. Because control is not required in the county, it is on the list of Non-Regulated Noxious Weeds for King County. A fall or spring herbicide application will be effective. Become a certified small business contractor or supplier, Find certified small business contractors and suppliers, Washington State Noxious Weed Control Board. Perennial thistles, Canada thistle being the major one, can exist for many years and they reproduce from both seed and underground parent rootstocks. Canada Thistle Identification. From the Fields - Alfalfa Growers Check for Sulfur Deficiency! It is native throughout Europe and northern Asia, and widely introduced elsewhere. Please click here for more information. Mowing is generally less successful on deep-rooted perennial weeds and brush. FIGURE 4. Thistle management consists of proper identification, and then combining various cultural, mechanical, chemical, and perhaps biological measures. The bracts beneath the flower heads do not have spines. The barbs must be removed from the leaves and the stems are to be shaved with a knife. Although leaves, stems and flowers are edible needless to say you must wear protective gloves and clothing when harvesting. After germination, they form a prostrate rosette ranging from 4 to 18 inches in diameter before becoming dormant in the late fall. The Canada thistle is a perennial species of flowering plant in the Asteraceae family. Most King County offices will be closed on Thursday and Friday, for the Thanksgiving holiday. The stems can be prepared as crudites, added to vegetable dishes or roasted. Jim Morrison, (815) 397-7714, morrison@uiuc.eduDate: August 7, 2005, by Jim Morrison, Extension Educator, Crop Systems, Plan A Local Pasture Walk - Promote Sustainable Grazing Management, Forage Options for Fall & Winter (August 2010). Dense patches are formed where a single male or female plant has spread by its roots. For more information, see Noxious Weed Lists and Laws or visit the website of the Washington State Noxious Weed Control Board. A) Bracts small and leaf-like, purple tipped, and collectively Click, All listed plants are found in central-east Canada and Biennials are most easily controlled by herbicides while in the seedling or rosette stage in the year of germination and up to bolting stage in the second year. The Canada thistle is a perennial species of flowering plant in the Asteraceae family. Comparatively, Canada thistle is a perennial that reproduces through underground rhizomes and wind-blown seeds. Wild food can help treat various medical conditions. From the Fields - Time to Check Alfalfa Stands! They occur alternate on the stem. After flowering or with the first frost, biennial thistles die in the second year. After bolting, they are much less susceptible to herbicides and mowing becomes the best option. The spiny nature of thistles prevents livestock from grazing near them and heavy thistle infestations may cause large areas of pastures to be left ungrazed. It is commonly found on roadsides, cultivated fields and pastures, logged forests, and other disturbed areas. Depending upon the livestock species, some herbicides have a legal interval between application and reentry for grazing/harvest. To support our efforts please browse our store (books with medicinal info, etc.). This thistle is also commonly known as the creeping thistle and field thistle. Some wild plants are poisonous or can have serious adverse health effects. A new broad-spectrum herbicide, Aminopyralid, manufactured by Dow AgroSciences, may be registered by the end of 2005. Perennials should be treated by a translocated herbicide while in the bud-to-early flower stage or in the fall regrowth stage. Exotic thistles can form dense infestations, often in disturbed areas. In-depth wild edible PDFs. This plant can grow anywhere up to 1.5 metres (4') tall. Canada thistle leaves measure 5 to 17 cm (2 to 8”) long, are narrow, with crinkled, deeply lobed, and spiny edges. Public and private landowners are not required to control infestations of Canada thistle that occur on their property in King County. Flower bracts are spineless. Canada thistle develops seed sparingly and may produce 1,000 to 1,500 seeds per flowering shoot. Identification, health, This thistle is also commonly known as the creeping thistle and field thistle. Using good cultural practices (including rotational grazing, maintaining optimal soil fertility, and periodic mowing) that result in vigorous, dense, and uniform stands will help keep pastures competitive with weeds. The creeping root system enables this weed to spread yearly. Canada thistle grows on every continent with the exception of Antarctica.