Purchased two Tansy plants today and I am most anxious to know if their invasive before planting these herbs. Do they have underground runners. Thank you for any information available. We are doing battle with a highly invasive plant that has taken over one of our gardens. Don't want to make that mistake ever again.
Tansy Hi, There are TWO plants that people call tansy Senecio jacobaea (tansy ragwort) and Tanacetum vulgare (common tansy). In some areas they are both considered noxious weeds. Here in the Fraser Valley, tansy ragwort is considered a noxious weed. This is due to the fact that it makes toxins which can eventually kill livestock, as well as being allergenic (the pollen is a common cause of hayfever). Plus it spreads like crazy (and so does common tansy, which is why it is a noxious weed in some other areas). They do not however, have any rhizomes or anything like that to worry about. They spread by making millions of seeds that float on the wind and get everywhere. The most obvious difference between the two is that the flower of the common tansy has no 'petals' and appears to be a yellow button, while the flower of tansy ragwort does have 'petals' (technically, ray florets). See these links: tansy ragwort:http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=SEJA http://www.fvrd.com/weeds_appearance.php common tansy: http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=TAVU
