Spartium junceum aka Spanish Broom

Spartium junceum is Spanish broom. Other names are rush broom and weaver's broom. It belongs to Fabaceae, the pea family. It is native to the Azores and southern Europe. Its range also includes the eastern Mediterranean. It grows in dry, rocky ground and scrub, often on limestone. This shrub grows fast and has several stems. Its shape is open and upright. Garden sources give heights and widths of 5–10 feet [1.5–3 metres]. Other accounts give heights of about 11.5 feet [3.5 metres].

Young stems are green, round, and thin, much like rushes. They branch near their tops. They use light to make food, a process called photosynthesis. Older stems form woody bark. The small, narrow leaves have smooth edges and no hairs. They grow sparsely and last only about four months. Sources differ on whether the shrub keeps or sheds its leaves. They call it either evergreen or deciduous. Green stems remain a key feature when the leaves fall. The bare shoots give the plant a loose, spare outline.

The bright yellow flowers look like pea flowers. They have a strong scent. Each flower reaches about one inch long. They grow at shoot tips in clusters called racemes. These clusters can reach about 18 inches in length. Missouri Botanical Garden gives a bloom time of July through September. NC State reports that bloom can last until frost. Bees and other insects help the flowers set seed through pollination. Flat pods follow the flowers and turn black. They reach three inches long. Ripe pods split open and scatter seeds, sometimes with a sharp crack.

Grow this broom in full sun and soil that drains well. It copes with poor, rocky ground, chalk, and drought. It also tolerates salt exposure on the coast. Sheltered sites can lead to long, sparse growth. Sources list USDA zones 8–10 and RHS hardiness H5. RHS warns that it is not fully hardy across the UK. Gardens use it for flowers and borders near the coast. They also use it to curb soil loss on slopes. Its stems yield fibre for cloth, cord, paper, baskets, and brooms. Flowers yield yellow dye and oil for perfume.

The shrub can spread by seed beyond its native range and become invasive. Dense growth can crowd out native plants. It can also raise the risk of fires in dry seasons. Some US states list it as a noxious weed. Most sources report few pest or disease problems. RHS flags it as a high-risk host for Xylella fastidiosa. Sources give no known edible uses. RHS warns that eating it can harm people and dogs. Past uses as medicine include a strong diuretic, which increases urine flow. Large doses cause stomach upset and purging.