Bringing more native plants to the San Lorenzo River levees is one of the key ways the Coastal Watershed Council is revitalizing the river’s habitat. When I host volunteer habitat restoration events for CWC, people often ask why we have stopped planting native plant seedlings along the levee. Here, I talk about our switch from seedlings to sowing native seeds as part of our habitat enhancement program! 

Why the change in planting? 

Let’s talk a bit about San Lorenzo River levee policy. This planting change is required due to the new direction given to the City of Santa Cruz by the U.S. Army Corps of Engineers (USACE). The policy prohibits any digging into the levee until a new Section 408 permit can be secured, which would give the City of Santa Cruz and/or the Coastal Watershed Council the ability to alter a USACE Civil Works Project (such as dig a hole in the levee). This was an originally unanticipated need, since a previous USACE inspector considered CWC’s project as falling under an existing 408 permit. 

This policy was a big change for the Coastal Watershed Council, and at first, we weren’t sure how to proceed. Last winter, I spent time in my role as River Ecologist reading policy documents, talking to restoration practitioners, meeting with Santa Cruz Public Works staff, and thinking about how to continue this work. After this extensive research, an idea started forming: if we couldn’t plant, maybe we could seed. Luckily, I had been spending time with a group working extensively with native plant seeds.  

So, what’s next for the plants? 

I had been volunteering with the Amah Mutsun Land Trust for a year, which is an initiative of the Amah Mutsun Tribal Band to restore indigenous knowledge and practices of land stewardship.  During this time, I gained extensive knowledge about traditional seeding techniques while helping the group in their own restoration goals. I also contacted the director of native plant stewardship for AMLT, Rob Cuthrell, who wholeheartedly supported CWC’s seeding transition by donating his time, research, expertise, and words of encouragement. This help was crucial to our planning and execution. 

How are we going to seed? 

Step 1: Planning the seeding pallet.

Just like an artist chooses colors, I first researched and planned the “pallet” of seeds we wanted to work with. After considering a lot of parameters, like soil composition, sun exposure, plant growth patterns, and plant vigor, we decided on seeding Purple Needlegrass (Nassella pulchra), California Brome Grass (Bromus carinatus), Blue Wildrye (Elymus glaucus), Yarrow (Achillea millefolium), Pacific Aster (Symphytricum chillense), Coast Tarweed (Madia sativa), Mugwort (Artemesia douglasiana), and Tall Flatsedge (Cyperus eragrostus). 

Yarrow (left) and Pacific Aster (right)

Step 2: Seed collection and contracting.

In 2023, we collected local seed at the Younger Lagoon Reserve with the permission and assistance of CWC volunteers as well as the reserve’s Director Elizabeth Howard and Restoration Field Manager Vaughan Williams. We also contracted Central Coast Wilds Nursery to collect even more seeds and received seed donations from Grassroots Ecology’s Nursery Director and Botanical Consultant Deanna Giuliano. 

Deanna Giuliano collects mugwort seeds

Step 3: We seed the site!

With the help of so many lovely volunteers, including Outriggers Santa Cruz, Downtown Streets Team, Santa Cruz Musuem of Natural History Earth Stewards, Gault and Bayview students, River Health Day community volunteers, and so many more, we have created 19 seed plots along the San Lorenzo River to date. To do this, we removed the weeds, softened the soil, sprinkled the native plant seeds, walked on them to tuck them into the soil, and then spread a thin layer of mulch to reduce weeds and increase moisture. 

Students with Earth Stewards sow mugwort seeds along the San Lorenzo River

Step 4: Tending the plots.

Throughout the next year, we will closely monitor and tend to the seed plots by removing weeds and supplementally watering if needed. 

Step 5: Do it all again!

With the information gained from this year‘s monitoring, we will repeat these steps, modify our techniques, and create more habitat and resources on the Lower San Lorenzo River! 

The Future 

We are not sure what the future looks like for this project and which seeds will flourish, but we do know that as of today our Coast Tarweed (Madia sativa) seedlings are starting to rise out of the mud and reach their stems and leaves to the sky. We can’t wait to try it again next year, of course with a lot of help from our friends maybe even you! 

Coast Tarweed seedlings (center) starting to emerge

Facebook Comments