This week’s Weed
ChiloquinNews article 16th July, 2012
Bachelor’s Button or Cornflower (Centaurea cyanus)
Most people love this brilliant blue flower at first sight. So easy to grow, so beautiful in a vase, and so famous in gardens, it’s a flower many people really enjoy in their wild meadows. However, it is aggressive in many places, and we are one of those places. North Carolina has actually prohibited it while in Oregon it is on the list of noxious weeds targeted for biological control. Here, Bachelor’s Buttons not only take over in gardens, they actually spread more rapidly into the wild and tend to dominate prairies and fields where they displace grasses, crops and native wildflowers. They are a real threat to the Palouse Grasslands of Washington, Idaho and northern Oregon.
A drought tolerant annual, native to Europe, it has naturalized throughout North America and parts of Australia, while in the UK it is now endangered in its native habitat largely due to the over-use of herbicides and conversion of land to agriculture. There, it has declined from 264 sites to just 3 sites in the last 50 years and there is an effort underway to ‘bring it back’.
In the past it often grew as a weed in crop fields (known as corn fields in Europe), hence the name cornflower. In folklore, cornflowers were worn by young men in love, giving rise to the name Bachelor’s Button. The petals of cornflowers are the part used in herbal folklore although it is not now thought that herbal uses for it are very effective. The Blue Cornflower has been the national flower of Estonia since 1968.
Because of its popularity as a garden flower the original blue has been hybridized to form other colors and cornflowers now come in shades of blue, purple, pink and white. But, delightful as these flowers may seem, enjoy them in the vacant lots around town where they are already well established, and don’t encourage them in your own backyard.