The Strategy: Scotch broom (Cytisus scoparius) is a perennial shrub from Europe and was most likely introduced as an ornamental. It is not generally found in this area although major landscape nursery retailers may bring it in as an ornamental to sell. It has been said that what they bring in is a ‘sterile’ variety, although research states there is no such thing. This woody species has alfalfa like leaves with yellow flowers, producing a pea-like pod and grows in large clumps up to ten feet tall. Its unique characteristic is that it has a 5 sided stem. It leaves a leafless woody stem to over winter almost like an evergreen appearance.

The Attack: This beautiful plant is highly competitive and grows much faster than our native species. Once established it becomes aggressive in growth and its deep tap root makes it difficult to control. Since it grows in sandy well drained soils it spreads where other plants do not survive. Like all legumes (peas, alfalfa) it self fertilizes and thus grows quickly. This is a huge problem in northern Idaho.

The Defense: Animals do not graze on it due to its woody stems. There are few insects that can be utilized on this plant with minimal success, therefore one must try to mechanically remove the weed (very difficult) or use herbicides. Herbicides specific to woody plant control should be used. Roundup Pro used early in the year will work (watch for off-target damage to grasses), but the best product is one called Garlon 3A (also known as Crossbow). Using this product when the plant is actively growing is a great choice, and it is not harmful to grasses and some forbs. Make sure you know what plant you are buying, if you are not sure call your county weed superintendent.

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.