Multiple departments are responsible for the various assortment of weed prone landscapes throughout the City, including greenbelts, storm basins, neighborhood parks and open spaces. City Departments with responsibility for weed management include: Community Development, Parks and Community Services and Public Works Utilities and Operations.
Weeds sprout up in the landscaping across the City every year. Weed maintenance contractors and staff work hard to control weeds across the City in a manner that has the least impact to people, wildlife and water quality. Inputs from the wet season will lead to more vigorous and denser weed growth in the spring and summer months. This in turn, increases the effort required to manage the landscape. However, the sheer size of the service area makes it an impossibility to manage all weeds, in all locations, at all times.
Current and Ongoing Strategies Throughout the City of Davis
The City continues to employ the assistance of a landscape contractor (Brightview), who uses multiple teams to conduct mowing/weeding within parks, greenbelts and street medians, in addition to targeted pesticide applications across the City. City staff are also conducting weed control in areas not serviced by Brightview.
An array of weed control methods are utilized by our maintenance teams including mechanical, cultural, biological and, when necessary, least toxic chemical control methods. Mowing, string trimming and mulch applications are performed throughout the week starting in the winter. Sheep grazing is also used to help reduce fire fuels and control unwanted vegetation in stormwater conveyance channels, facilities, levees, basins, recreational greenbelts and pedestrian trails during the spring and summer months. Herbicides are strategically used within street medians and around utility sites.
City staff are working on the development of site management plans for high traffic and highly visual areas to include: seasonal weed growth, proposed timing for each control methods (mechanical, chemical, cultural and biological) and targeting weed species when they are at their most vulnerable (primarily during the growing stage).
Staff are working to control several priority weed species (ex. yellow starthistle, bermudagrass, perennial pepperweed, etc.) throughout all of our sites using a combination of IPM techniques. Trail edges along all of the City’s Open Space sites are regularly mowed starting in March to keep weeds (especially foxtail) away from the publicly accessible areas and to reduce fire hazard.
Integrated Vegetation Management (IVM) methods includes:
- Mechanical weed control are physical activities that inhibits unwanted plant growth. Mechanical, or manual, weed control techniques are physical methods to help remove or make the growing conditions unfavorable. These methods typically include mowing, string trimming, physical barriers and others.
- Cultural weed control are practices that help desirable vegetation become more competitive against weeds, or maintains native vegetation conditions so weeds are less likely to become established and/or increase in number. Some examples cultural weed control include hand pulling, mulching, cultivation, prescribed grazing or burns, volunteer assistance, and site removal of vegetative cuttings when practical or imperative.
- Adjusting irrigation rates and identifying irrigation sites with excess weed growth to adjust irrigation practices.
- Chemical weed control, where appropriate per the City's IPM policy, may be utilized to control problematic weeds and increase durations between necessary treatments of landscaped areas. Well timed herbicide applications (either with pre or post-emergent products) can help prevent seed development and suppress the spread of weeds.
- Reducing seed set through well timed herbicide applications (either with pre or post-emergent products), site removal of vegetative cuttings when practical or imperative, mulch raking and replenishment in landscape beds to disrupt germinating seedlings.
- Monitoring effectiveness of herbicide applications by tracking effectiveness of herbicide applications for sites on targeted weed species. This includes discontinuing or rotating products to achieve desired weed control.
- Contracted services are utilized by departments with the intent of mobilizing landscaping professionals to areas where service requests have been received and deemed as high priority.
