We had this innocent-looking large bush in our front yard for probably 20 years. It had drip irrigation, but maybe that wasn't enough because as our area became drier and hotter with climate change, the bush stopped flowering. We had forgotten the name, but we recall buying it at Home Depot as a little one-foot plant. 

Last year, I supplemented the drip with hose watering, and also periodic fish fertilizer.  The mysterious bush rewarded me with a surprisingly glorious display of multi-colored blooms.

Sadly, it appears to have been the plant's swan song, because after the flowering, and in spite of regular watering, it inexplicably died shortly thereafter.  I was devastated (ok that's an exaggeration, but I did feel quite sad).  Plants that actually do well in my yard are precious.  It was only then, while searching for a replacement, that I learned this is a highly invasive scotch broom.  It was impossible to find for purchase at any big box store or independent nursery within driving distance. 

The bright yellow broom is apparently most common and what many people know to be invasive.  The one we had was a variegated version.  After an exhaustive online search, I finally found what appears to be the closest to my bush, called 'Sister Rosie' Scotch Broom.  Sadly, probably because broom is considered highly invasive in California, online retailers carrying the plant cannot ship it to me. 

Interestingly, in the 20 years we had our broom, it never once produced a single seedling.  Goodbye, gorgeous Sister Rosie.  I didn't properly appreciate you until it was too late.  Good thing you were just a plant, and not a person!