From habitat restoration to home brews, rhizomes rule


A rhizome is a modified stem that grows horizontally below the soil surface. Rhizomes are full of starches and proteins, and as they grow, they are able to sprout new shoots that feed off this food source. This allows the plant to essentially “clone” itself, spreading from its original seedling to occupy more space.

In coastal marsh restoration, propagating rhizmonious species is a useful tool.  At many of our restoration sites around the San Francisco Bay, the shoreline is infested with invasive plants. These non-native species thrive on the disturbed soils of bay fill and get a head start on our California native plants. In order to successfully restore a site, it’s a tough battle between these invasives and the native plants we grow. Through our community based restoration programs, volunteers are able to pull these invasive species as they sprout, but that is only half the battle.

creeping wild rye
Creeping wild rye, spreading through its rhizomes at our site at Eden Landing Ecological reserve in Hayward.

The ultimate goal is for the native plants to become fully established so they can keep invasive plants from growing themselves. This is where the rhizomes come in. Being able to spread vegetatively through these underground stems, the native plants such as Marsh Baccharis, Creeping Wild Rye, Western Goldenrod, and California Bee Plant, can spread at a faster rate in addition to producing seed. As these rhizomes spread they compete with invasive seedlings for water and nutrients from the soil, as well as space and access to sunlight.  It’s amazing to watch these native plants spread from their original seedlings to form dense stands of vegetation, the perfect cover and habitat for many species living in and adjacent to the marsh.

Hop rhizome
Hop rhizomes used to make beer.

Not only are rhizomes amazing from a restoration viewpoint, we also rely on them for several tasty foods. Hops used for brewing and flavoring beer also grow from rhizomes. Asparagus sprout from these modified stems as well, and the ginger root used in cooking and making teas is actually a rhizome itself!

Come see how cool rhizomes are yourself by transplanting Creeping Wild Rye rhizomes at one of our public nursery programs held every 1st Wednesday of the month, or help in the ongoing battle against the invasives at one of our Saturday public programs in the field! Sign up to volunteer online.

Growing Beardless Wildrye to Restore the Bay’s Shoreline

beardless wildrye
Beardless Wildrye helps stabilize the transition zone along the edge of the Bay.

Beardless Wildrye, Elymus triticoides, (formerly of the genus Leymus), is a beautiful and highly adaptable grass species that historically occupied large swathes of lowlands and floodplains throughout the salt marsh transition zone throughout the Bay Area.  Its range extends from California to Washington, and inland to Montana and West Texas.  It is found in meadow landscapes, from dry to moist soils, often where soils are more saline.  It is a cool-season, perennial grass and is considered to be strongly rhizomatous, or sod-forming.

Save The Bay propagates this species by collecting rhizomes – underground, horizontal stems that produce new plants — from a variety of locations near our project sites. A small percentage of rhizomes, shoots, and roots are carefully dug out of the soil and brought back to the nursery to be divided and grown in individual containers for one season, and finally planted during the winter months to colonize locations formerly occupied by non-native annuals such as mustard, radish, Italian thistle, and fennel.

This grass is part of a suite of species that grow by rhizome in the transition zone.  These sod-forming species form layers of roots below the soil surface, somewhat like threads of fabric that stabilize the soil and prevent invasive species from growing.  Above ground, dense vegetation provides critical habitat for insects, small mammals, and ground nesting birds.  As shoots die back each season, thick layers of thatch form, providing more layers of habitat and preventing other species from entering into the system.  Rushes, sedges, grasses, and broadleaf herbaceous perennials, work together and share site dominance over time. During years of higher precipitation, certain species thrive in more freshwater and during drought seasons, other more salt-tolerant species will dominate the system.    This is a very important function of established transition zones in terms of sea-level rise and increasing hydrological fluctuation.

To learn more about propagating beardless wildrye and other native species that grow along the edge of the Bay, join us at our native plant nurseries the first and second Wednesday of each month from 1-4pm.  Check out our website for more information on how you can get involved.

Happy spring!

— Doug Serrill, Nursery Manager