Scotch broom, although a delightful shrub, is not to be planted everywhere. This European native fought with other plants to secure its own living space in its native habitat. This gave Cytisus scoparius strong resilience and adaptive power that makes it very invasive in many other places!
In many states in the USA, it’s declared an invasive weed. With the maps below, you can check for yourself whether or not to plant it. Sometimes local governments even have programs you can join in on to help eradicate the scourge!
| Native to | Europe |
|---|---|
| Invasive in | Oceania, North America, East Asia, portions of South America, Central Asia, South Africa |
Scotch broom was first admired by botanists for its bright yellow blooming and dense growth. Horticulturists happily offered the plant, and others of the Cytisus family, for purchase to their customers for landscaping purposes.
However, in the late 20th century, awareness rose about how invasive the plant could be. There wasn’t even any point in letting it grow, since the shrub doesn’t make for good fodder. Additionally, it is rated as an extreme fire hazard: a few licks of a candle and the entire shrub might ignite in dry weather.
Many state and national programs today try to eradicate this threat to local biodiversity. In California, a particularly fire-prone state, fire prevention plans even call for pulling the plant out wherever possible.
Native range: Austria, Belgium, Belarus, Bosnia and Herzegovina, Czech Republic, Croatia, Denmark, France, Germany, Hungary, Ireland, Italy, Lithuania, Kosovo, Moldova, Montenegro, Macedonia, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Serbia, Sweden, Switzerland, Ukraine, United Kingdom
Invasive range: Australia, New Zealand, Canada, United States, Japan, Chile and Argentina, India, Iran, South Africa (the country)
In green, on the map below, you can see where the plant is native to. Even within these areas, however, it is sometimes listed as an invasive weed because it can take over land from less combative species.
The same shrub behaves very differently depending on where it lands. Here is how the article’s ranges break down before you decide whether to plant it.
| Region | Status | What to expect there |
|---|---|---|
| Europe | Native | Still listed as a weed in places, as it can take over from less combative species |
| United States, West Coast | Invasive | Sprouts on bare ground after fires and dominates all other native plants within a few years |
| California | Invasive and an extreme fire hazard | Fire prevention plans call for pulling the plant out wherever possible |
| Oceania, East Asia, South America, South Africa | Invasive | Recorded from Australia and New Zealand to Japan, Chile, Argentina, India and Iran |
Many state and national programmes are now working to push these populations back.
The University of Georgia manages a mapping system to report sightings of scotch broom across the United States. The Early Detection and Distribution Mapping System program makes it easy for volunteers to signal the presence of this plant with accurate localization.
Here is the most recent version of the map for Scotch or Scot’s broom:
Where Scotch broom is safe to plant, named cultivars offer far more than the plain yellow of the wild type, with tidier sizes and two-tone flowers. Remember that these garden forms still set seed, so keep them well away from wild ground.
| Variety | Flower colour | Best use |
|---|---|---|
| ‘Lena’ | Ruby red and gold bicolour | Small gardens, large pots |
| ‘Burkwoodii’ | Crimson with gold-edged wings | Sunny focal shrub |
| ‘Boskoop Ruby’ | Deep ruby red | Mixed shrub border |
| ‘Andreanus’ | Yellow with crimson wings | Dry banks, poor soil |
| ‘Zeelandia’ | Cream, lilac-pink reverse | Pastel planting schemes |
| ‘Goldfinch’ | Yellow flushed red and pink | Gravel and coastal gardens |
Status, legality and regulations about Scotch broom
In the United States, Scotch broom is especially problematic along the West Coast. Weather patterns there often lead to dry seasons and fires wipe native plants out. Then, on bare ground, Scotch broom sprouts and dominates all other native plants within a few years.
On the following map, you can check whether the plant botanists call Cytisus scoparius is officially registered as a weed in your state.
Don’t fall for the trap of burning off patches of Scotch broom. Seeds are fire-resistant, and it will sprout back much faster than other native plants! Better to pull them out or prune them to a stump once a month until the root system is drained and dies off.
