The Enemy: Small bugloss (Anchusa arvensis) is a noxious weed that was brought to us from Europe. This weed is a problem in cultivated fields as well as near other disturbed sites such as ditch banks and empty lots. It has a single taproot, leaves are alternate with wavy margins and the entire plant is covered with bristly hairs. The small blue flowers are funnel shaped with a distinct curve in the whitish tube. The flower produces seeds in 4 nutlets, which overall can produce 250 seeds per plant.
The Strategy: This nasty weed starts growing in the late fall which gets it a head start over other vegetation that generally grows in the spring. It is quite a good survivor, in fact where it was found has been treated with Roundup and 2,4-D and it grew back. It is toxic to livestock as are most of the plants in the borage family. This plant grows like a small round bush and blocks the sunlight from reaching desired plants and removes valuable nutrients from the soil.
The Defense: As this is an annual mechanical control is feasible as long as there is just a few plants. There are no insects that will eat it so biocontrol is not a tool for this job. Herbicides are effective as long as they are applied early in the spring. As this plant is very bristly, leaf coverage is key to controlling it with herbicides. This is best accomplished by using good quality surfactants and larger volumes of water. Please, please contact your local County Weed Superintendent if you suspect this new invader has encroached on your property, early detection and rapid response are key.
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.