(Cytisus scoparius)
Scotch broom is an evergreen shrub, with bright yellow, pea-like flowers that may have red markings in the middle. Stems are woody and 5-angled, with lower, stalky leaves composed of 3 leaflets and upper, un-stalked leaves. Flat, hairy seedpods are initially green, turning brown or black with maturity. Scotch broom grows to 1-3 metres in height at maturity. Scotch broom spreads by seed and lateral bud growth, and mature plants can produce up to 3500 pods, each containing 5-12 seeds. As seedpods dry they split and spiral, expelling the contained seeds up to 5 metres. The plant can also spread to new disturbed areas through seed transport by vehicles and machinery. Due to its affinity for light-dominated, disturbed areas, any disturbance activity, such as road or home construction near infested areas, can enhance spread. Scotch Broom invades rangelands, replacing forage plants, and is a serious competitor to conifer seedlings; Douglas fir plantation failures in Oregon and Washington have been credited to infestations of this plant. High density infestations can: 1) increase wildfire fuel loads, thereby escalating wildfire intensity; and 2) obstruct site lines on roads, resulting in increased maintenance costs for removal. Dense thickets may be impacting Garry oak woodlands in southwestern BC and limit movement of large animals. Photosynthetic stems enable year-round growth, leading to displacement of native plant species. Refer to Scotch Broom T.I.P.S. for information on prevention and control methods. |
