Common Rush: A Defensive Line Along the River

In the spirit of learning, the Coastal Watershed Council invites you to explore and learn more about native plants growing along the lower San Lorenzo River. Every second Saturday of the month, CWC leads River Health Days where volunteers help plant, water and care for a variety of native plant species to increase biodiversity and habitat complexity and support a healthy river ecosystem. Common Rush (Juncus patens) is one beneficial native plant that you might spot growing along the river.

What does it look like and where can I find it?

Common Rush can be identified by its tight bunches of rounded, stick-like stems that are typically blue-grey in color. These stems can grow to be up to 3 feet tall. At the tips, reddish-brown capsules decorate the stems once the plant has matured and the flower has dried. In the late winter, Common Rush may look a bit dry as its capsules fall to the ground, but it is simply making way for new growth in the spring.

Common Rush tends to thrive in moist soils and becomes more abundant closer to the riverbank. You can often find it near other moisture-loving plants like willows and sedges. A common place to spot Common Rush along the lower San Lorenzo River is at the base of the slope running down from the Santa Cruz Riverwalk. Common Rush is native to the west coast of North America, so it can be found all along the California coast.

How did humans use it?

Due to its long, sturdy stems, Common Rush has historically been used by Native Americans for basket weaving, thatching, tying and binding.

What’s its ecological function?

During rain events, stormwater runoff can wash harmful pollutants and excess sediment down the riverbank, threatening the health of the San Lorenzo River. Luckily, Common Rush acts as a defensive line along the river and provides stellar filtration services. Its tightly bound stem and root structure allows it to trap, slow and sink sediments and pollutants before they can enter the water.

What can you do?

Last year, CWC volunteers planted 275 Common Rush along the riverbank and 100 more will be planted this upcoming winter. You and your family can make a difference in the San Lorenzo River ecosystem by caring for Common Rush and other plants that provide ecosystem benefits. Consider joining us for our monthly River Health Days along the banks of the San Lorenzo River where volunteers of all ages can take action to enhance river habitat. Sign up below!