Things You'll Need
Spanish broom, or Spartium junceum, is a perennial flowering shrub native to the Mediterranean basin. Like most Mediterranean plant species, Spanish broom is hardy and thrives under arid conditions with little supplemental water, sending up 6- to 12-foot-tall stalks topped with pea-like yellow flowers in summer. The most important aspect of Spanish broom care is proper planting since this will determine the overall vitality of the plant, but it is otherwise a very low maintenance species and requires only light pruning and watering once established.
Select a suitable spot for planting Spanish broom. Look for a spot with full sun and excellent drainage, but do not worry about soil type since it is not a picky species. Avoid shaded areas since the shrub will become leggy and thin-looking.
Dig a planting hole for the Spanish broom shrub measuring two to three times the volume of the original container. Line the bottom 2 inches of the hole with coarse sand to increase drainage. Settle the shrub in the hole and fill in around it.
Water the Spanish broom plant deeply to approximately 4 inches immediately after planting. Water the shrub no more than 1 to 2 inches every 10 to 14 days after the initial watering. Avoid any supplemental water in moist, rainy climates or during periods of steady precipitation.
Prune the Spanish broom shrub periodically during the flowering season. Remove the spent flower heads as they occur using a pair of sharp, sturdy pruning shears. Snip the stems straight across just above a pair of leaves to encourage a bushy shape in the plant.
Hard prune the Spanish broom in late winter to control its size. Cut the stems to a uniform length using pruning shears. Remove no more than one-third of the old, woody growth when hard pruning the shrub to keep it from going into shock.