The Enemy - Oxeye daisy (Chrysanthemum leucanthemum) is perennial growing to a height of 3 feet. The flowers are white with a yellow center which resembles many of the other daisies that are out there. The plant spreads by seed or by roots, which gives it a great advantage over other plants. Each plant can produce over 25,000 seeds, and uniquely these seeds can germinate immediately, and remain viable for over 35 years. This plant greatly resembles Shasta daisy and is still considered an ornamental plant. It has been found along some of your roadsides and ditch banks, but if you have ever been to northern Idaho you can see how this plant is taking over the native habitats.
The Strategy - Oxeye daisy has the ability to invade many sites such as cereal grain crops, meadows and pastures, and around here we have seen it mostly on ditch-banks. It grows so dense that the field look as if they have a blanket of snow over them. It is generally not consumed by livestock, but if eaten by the cow the milk will have an ‘off’ flavor. Since the plant can spread by its rhizomatous roots it can spread into neighbors lands.
The Defense - As this is another of those pesky perennial plants, digging or disking of the land is not effective. As of date there are no bio-control insects available to help control the weed. Herbicides such as Curtail, Redeem, Tordon, and Milestone are the best. If you can’t catch the weed early in the spring, then waiting until you can see the buds forming will be the best opportunity. As this species favors low fertile soils, and application of nitrogen fertilizer can help deter it from being a problem. Oh, and next time you decide to plant wild flowers, make sure the package does not contain this invasive weed.
PLEASE NOTE -The proper use and application of herbicides can be an effective way to control and eradicate noxious and invasive plants. Before using herbicides, always carefully follow the label and safety instructions on the label. While we recommend the use of herbicides as one of the effective tools for integrated pest management, the Idaho Weed Awareness Campaign assumes no liability for herbicide applications.
For more information, click on the link below to download the Idaho's Noxious Weeds Control Guidelines publication produced by the University of Idaho Extension.
U of I Idaho's Noxious Weeds Control Guidelines (183 KB PDF download)