I remember when I was a kid, and first learned that the pretty yellow-flowered bushes I saw all over were bad for the environment. It was probably my first ecological lesson, and I was heartbroken. Their sunny color had always made me happy when I looked out the window on family drives. How could I have been so wrong?
Since then, Genista monspessulana has only become more common. You can see it filling the understory of forests on Mt. Tam, or spilling over the cement retaining walls along roadsides. This highly invasive plant is native to the Mediterranean and the Azores, and was brought to California in the 1800s — probably as an ornamental for gardens. It really is quite pretty. But it also is what scientists call an “ecosystem disruptor” because it wreaks havoc on the native plant communities. It forms dense stands up to 16 feet tall, under which nothing else can survive. All the delicate flowers, grasses and even hardier shrubs perish in its shadow. Livestock don’t even like to eat it. Broom is like an ecological bulldozer, taking diverse habitats and leaving a barren landscape in which it is the only survivor. A single plant has been found to produce over 30,000 seeds — and the seeds live for decades in the soil, waiting for a disturbance like digging (or pulling a grown plant out by the roots) before they sprout. It also is a fire danger, growing tall and tinder dry. Can you tell how I feel about this plant? It’s a nightmare. If you have it on your land or in your neighborhood, get rid of it!! Quick, before it spreads!