Scotch Broom (Cytisus scoparius)

Factsheets

Description

Bushy, green, woody shrub with a  woody brown main stem and green branching stems. Flowers are yellow and pea-like, followed by dark pea-shaped fruits that split when dry. Green stems can photosynthesize year-round. Can grow up to 3 meters tall.

Habitat

Scotch broom originates from the European Mediterranean, and thrives in full sun on mineral soils.  On Galiano Island, it is common in power-line right-of-ways, roadsides, clearings, and disturbed forests; it will also move into Garry oak meadow ecosystems and coastal bluffs.

Impact

Scotch Broom is considered toxic to wildlife, and displaced native species in open ecosystems. It spreads rapidly due to large numbers of seeds (up to 35,000 per plant!) that linger in the soil seed bank for decades, and fixes atmospheric nitrogen into the soil, favouring non-native species.  High densities of plants can smother wildflowers, prevent tree regeneration, and increase wildfire danger.

Management

Cut broom anytime before it starts producing seeds (usually before the end of June), ideally when it is in full bloom. Cut the stem as low to the root crown as possible.  All flowering individuals in a population should be removed annually.  Patience and persistence are needed, as it will take at least several years to several decades to exhaust the seed bank in any given site.

Small plants that are not yet producing flowers can generally be left alone, as young broom has a high mortality rate.  Wait until they bloom, then cut them.  Broom without seed pods that has been cut can discarded in the forest in shady areas, provided it is located where it will not result in a fire hazard.  Broom with seed pods should be burnt.

Our Experience

With many years of concerted effort, we have found that even overwhelmingly large populations of Scotch broom can be controlled and eliminated.  Consistent annual cutting is the key, as missing even one year can lead to significant setbacks.  Broom should be removed whenever possible from sensitive ecosystems such as Garry oak woodlands and coastal bluffs.

Uses of Harvested Scotch Broom

Plant can be used to create yellow and green dyes. For large plants, the woody stems are especially strong, and can be used in woodworking and crafting. Flowers and flexible branches can be used to create summertime wreaths and bouquets.

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