Spanish broom makes a nice addition to any yard, but works well in a xeriscape-style landscape. Once established, they do take less water than other flowering bushes, but from my experience, more water or rain in the Spring contributes to a thicker cover of blooms. Mine blooms anywhere from April to June for about two weeks, and the rest of the year is a nice dark green. The best thing about Spanish broom, however, is the lovely scent of those flowers, and the computer does not allow me to share that with you.
About the only drawback I can think of with this plant is that it will get very large, so put it where it has plenty of space to grow, or be prepared to prune it about every other year. On the other hand, if you let it grow too big, the branches get heavy and it splits in the middle and loses it pretty ball shape. So keeping it pruned and shaped on a fairly regular basis keeps it looking its best, even if it has room to get huge.
According to Dr. Curtis Smith of the New Mexico State University Cooperative Extension Service in Albuquerque, the best time to prune is during the dormant season and to do what’s called rejuvenation pruning. Remove the old stems at ground level. My Spanish broom is probably ten years old, and we have pruned it twice by just cutting it back all over about one to two feet from the ground, so we have missed our window for the rejuvenation pruning, as it now has such a thick mass of branches at the base. Dr. Smith would disapprove of how we cut it back because he says if you prune partially, the stem will produce a cluster of new branches near the pruned end, making a broom-like growth. Mine may do that, but it also comes out from the base of the branches at ground level. The plant is very forgiving, so prune in whatever fashion works for you, but I would prune from time to time!
And come Spring, enjoy the wonderful aroma as well as the burst of yellow flowers.
Information gather from this site: http://aces.nmsu.edu/ces/yard/2005/101505.html