ROSE CREEK WATERSHED INVASIVE PLANT CONTROL PROJECT
Weeds Out, Natives In
In 2012, The Chaparral Lands Conservancy began implementation of a major project to remove harmful invasive plants from the Rose Creek Watershed. Located in central San Diego, the Rose Creek Watershed includes a system of canyons chock full of wildlife amidst the dense City of San Diego suburban communities of Clairemont and University City. Rose Canyon and San Clemente Canyon form the core of the Watershed, arising from chaparral hills and mesas on Marine Corps Air Station Miramar, draining west through oak and sycamore filled Rose Canyon in University City and San Clemente Canyon in Clairemont (alongside State Route 52) to where both canyons meet near Interstate 5 and drain into the north end of Mission Bay.
INVASIVE PLANTS POSE MAJOR THREAT
Dense human communities can pose a significant threat to the ecological health of nearby natural canyons in the form of escaped, non-native, invasive plants. Some of the worst offenders are ice plant, giant reed, Pampas grass, and eucalyptus trees as they spread rapidly, displace native plants and animals, and increase the risk of fire and flooding in creeks and canyons. Eucalyptus trees have shallow roots and are a threat to public safety when they topple in wind storms. Falling limbs are another public safety threat from eucalyptus trees that have been infested and weakened by a type of wasp. Oil in eucalyptus leaves suppress the growth of native plants and soil bacteria, creating dead zones with few native species.
Pampas grass and ice plant grow in dense patches to the exclusion of any other plants. All of these invasive plants crowd out native plants like oak trees and California sagebrush that would otherwise provide a home for native wildlife like bobcats, gray foxes, barn owls, acorn woodpeckers, and California gnatcatchers.
INVASIVE PLANT REMOVAL NOW UNDERWAY
Following years of planning led by Ann Van Leer of the Land Conservation Brokerage and San Diego EarthWorks, The Chaparral Lands Conservancy has received grants and donations and secured agency permits to implement the project. Starting in the fall of 2012 and continuing for several years, the Conservancy’s contractor, RECON Environmental will work to eradicate several select invasive plants. Herbicides are an important tool to remove invasive plants and their use has been approved by several agencies. Herbicides are designed for application near streams and are similar to Roundup. RECON employees are specially trained and certified to apply herbicides. A blue or green dye is added to the herbicide to mark treated plants, and treated plants may be retreated in subsequent years or reduced by cutting dead plant materials to the ground. In many cases, native plants will quickly colonize areas where invasive plants have been removed, and the Conservancy is pursuing future projects to replant native plants in treated areas to speed recovery of native habitats.
PUBLIC EDUCATION AS LONG-TERM SOLUTION
The Rose Creek Watershed Invasive Plant Control Project will be coordinated with a complimentary program to educate watershed residents and nurseries about non-native invasive plant species and the importance of choosing landscaping alternatives. An “adopt your watershed” program will also be conducted to educate nearby residents, businesses, and groups to reduce future invasive plant problems. One exciting element of the project brings together removal of invasive plants and educational outreach at University City High School where RECON will remove a dense stand of stunted eucalyptus trees and students will subsequently replant the area with native oaks, willows, and other plants, water the plantings, and study the results.
YOU CAN HELP!
If you live in the watershed you can help by removing any invasive plants from your property. Contact Rose Creek Watershed to see if volunteers are available to help. Check out the Don’t Plant a Pest brochure for native plant landscaping alternatives that are not only beautiful but can also save money with less water and fertilizer. You can also visit the California Invasive Plant Council or PlantRight to learn more about invasive plants.
The Chaparral Lands Conservancy is grateful for supporters who have provided funding and time to make the Rose Creek Watershed Invasive Plant Control Project a success, including:
- Ann Van Leer, Land Conservation Brokerage
- Deborah Knight, Friends of Rose Canyon
- Julie Fontaine, Trestles Environmental
- Mark Carpenter, KTU+A Planning and Landscape Architecture
- Kelly Makley, San Diego EarthWorks
- State of California Wildlife Conservation Board