The Scotch Broom is a large woody shrub, averaging 3-6 feet, that bears tiny yellow flowers and is related to the pea family. The plants bloom between March and June before the leaves emerge. I have 3 plants in different areas of my yard, and I love them. In 8 years, I have never had a problem with volunteer plants due to it's reported excessive self sowing.
However, according to the Oregon State Community Extension Service, it is a very invasive plant in the Pacific Northwest. The Scotch Broom is a native of Europe and North Africa, and was introduced in the 1850's as an ornamental plant in California and later used to prevent erosion and stabilize banks and dunes. There is no hatred for this plant on the East Coast where it doesn't appear to have the negative characteristics the folks on the West Coast talk about. I will keep a close watch on mine. On the positive side, Wikipedia states that as a legume, this shrub can fix nitrogen in the soil through a symbiotic relationship with Rhizobium bacteria. Something else to consider if you have small children or dogs, all parts of the Broom are poisonous.
On a more light-hearted note, I am back on bunny alert. A little guy has taken up residence under the backyard deck. This bunny is so small, it looks like one of those yard decorations with a hollow bottom for a hidden key. Adorable.