Cunningham Marsh Preserve

Managed in partnership with California Department of Fish and Wildlife, Cunningham Marsh is a unique wonderland in Sonoma County. This wetland historically supported a rich and distinctive wetland flora, including endangered plant species and many disjunct populations of plants typical of northern bog-like habitats. Home to one of two remaining populations of the Pitkin lily, Lilium pardalinum ssp pitkinense, a federally listed endangered species first discovered by Milo Baker in 1949.

Suksdorf Hawthorn at Cunningham Marsh Preserve

Suksdorf hawthorn Crataegus gaylusaccia

Rhododendron at Cunningham Marsh

Western azalea Rhododendron occidentale

Pitkin Lily at Cunningham Marsh Preserve

Pitkin lily, Lilium pardalinum ssp pitkinense

Photos courtesy of Gary Hundt


In addition to the lily, Cunningham Marsh has historically supported ten rare and endangered plant species, three of them federally listed, and one federally listed invertebrate species. We currently know of one rare species on the site aside from the lily. The marsh and upland had been grazed for the last century, with cows allowed to roam freely through the site. When the family that owned the property wished to develop it, CDFG and Betty Guggolz (CNPS) negotiated with the family to create a 19-acre Conservation easement in 1998. The easement, but not the land, is owned by CA Dept of Fish and Wildlife with CNPS agreeing to steward the site. The land is owned by four surrounding property owners.

Current Conditions

Due to grazing, organic matter has increased in what historically was a low fertility, low acidic pH, sandy substrate. In areas tested, pH was close to 7 in what was probably soil closer to 5.5-6 pH. Annual grasses planted for grazing have produced a highly organic surface layer of soil. Annual and perennial grasses still exist on the site. Areas in the upper part of the marsh that would seem to be appropriate lily habitat had been overtaken by Himalayan blackberries.

Preservation Goals

  1. To preserve and enhance the existing population of the Pitkin lily
  2. To restore upland wetland habitat with acidic sandy substrate conducive to the Pitkin lily and other rare species
  3. To remove invasive species and restore freshwater wetland and upland oak savannah

Progress to date

CNPS has been stewarding the site for many years, under the guidance of Jack and Betty Guggolz before the easement was established in 1998. After the easement was in place, volunteers continued under the guidance and expertise of Betty Young in maintaining all lily exclosures.

Most work has been weeding and removing blackberry from the immediate vicinity of the lilies. Lily counts have increased 200% due to this work. In several of the areas where Himalayan blackberries were removed, the area was overtaken by purple velvet grass (Holcus lanatus), causing a thick mat of thatch which prevents emergence of any seedlings.

In 2004, a Vegetation Management Plan (VMP) was written by Dr Peter Baye. It is available on our website, see a link below. Since the VMP was completed, grants have been received from The Community Foundation (Wine County Weekend), US Fish and Wildlife Service – Species Recovery Fund and Partners Fund (USFWS), and the Mary A Crocker Foundation.

In partnership with the Laguna de Santa Rosa Foundation and a loyal crew of Milo Baker volunteers, we have mowed the upland annual grasses twice per year, blackberries have been removed around the exclosures protecting the lilies from predators. Exclosures have been added, and some were expanded and enhanced. Seed was collected from appropriate local native species to create a hedgerow to filter nutrients coming into the site from the west where cows still graze and from landscape fertilizer from the homes on the east. Western azaleas and other wetland plants along with Pitkin lilies were added to the wetland. Oaks were added to the upland dominated by annual grasses. Planting took place in 2008-2009. Currently, the hedgerows provide a transition from the wetland to the upper area dominated by non-native grasses.

In the last 2 years, a USFWS grant funded the Laguna Foundation in a concentrated effort to control the purple velvet grass and blackberry. The marsh has been transformed. Purple velvet grass has been removed within the exclosures and controlled in the surrounding areas to prevent re-infestation. Jan Lochner and her intrepid team of Invasive Removal Volunteers have been cutting back blackberry, and removing purple velvet grass and other non-natives.

Future plans

Dependent on additional funding, include: removal of non-native, thirsty Monterey pine trees to provide more sun to the lilies, and to increase the water table, to continue control of purple velvet grass and blackberry re-sprouts. Piles of removed thatch, blackberries and downed wood will reduce fire danger through controlled burning, and will promote germination of native seed in the soil. The grants have allowed duties not appropriate for volunteers. However, the success of restoration at Cunningham is clearly dependent on volunteer support.

Volunteer activities needed

  • Continued careful weeding around lilies. This has been the single most successful activity with direct results in lily production.
  • Cutting back blackberries near native plants that cannot be mowed.
  • Mulching with conifer chips to prevent annual grasses and reduce pH.
  • Collecting native seed.
  • Performing botanical surveys.
  • Monitoring for lily seedlings and search for other native species throughout the marsh.
  • Divide rushes and sedges and replanting in new areas previously dominated by purple velvet grass.
  • Removal of other invasives throughout the site.

For more information: view the Cunningham Marsh Vegetation Management plan Cunningham Marsh Vegetation Management Plan

Updated by Marcia Johnson and Betty Young (March 2021)