August 2025

Greetings as we near the end of summer! I just returned from a conference and visit to the East Coast, and it was a good reminder of why we need to be vigilant about invasive species—spotted lanternflies were so prevalent in Baltimore that several of them landed right on me, and I got to witness a positively mind-blowing infestation of jumping worms at a family friend’s garden in Massachusetts (see below if your stomach is up for it). In more positive news, there were dozens of urban-focused talks at the Ecological Society of America Annual Meeting, and it was inspiring to see how many people are working to understand and improve our urban landscapes.

In this issue of Taproot, you’ll find new resources for managing weeds and urban tree canopy, information on upcoming trainings and events, and some fascinating recent publications.

Please feel free to share this newsletter with anyone who might be interested, or direct them to sign up here.

Best regards,

Joanna Solins

Environmental Horticulture Advisor

UC Cooperative Extension

Sacramento, Solano, and Yolo Counties

jsolins@ucanr.edu

Revised Weed Management Guidance

Bermudagrass and nutsedge are the bane of my existence right now (anyone else?), but luckily there are newly revised management guidelines available from UC IPM. Check out updated Pest Notes for bermudagrass, nutsedge, and Russian thistle.

New Urban Tree Canopy Tools

CAL FIRE and the USDA Forest Service released an interactive mapping tool that shows California’s urban tree canopy and how it has changed from 2018-2022. The map viewer overlays tree canopy with other information like census data and heat severity, and the canopy GIS files are also available for download. The data suggest that most municipalities in Sacramento County gained canopy, while most in Solano County lost canopy. This tool provides a great place to start for management and planting prioritization. Find the viewer, data downloads, and more information here.

In case that tool wasn’t enough, there is now another nationwide urban tree canopy viewer available through a collaboration among the Arbor Day Foundation, the USDA Forest Service, and PlanIT Geo. This tool also shows canopy change, but over a slightly different period—for our area, it’s 2016-2022—and statistics are shown by census areas instead of municipalities. A more nuanced canopy change story emerges for our region, with different areas of each city gaining or losing canopy.

Depending on your data and management needs, either tool could be a good choice. I suggest checking them both!

California Nursery Conference

Ventura County Agriculture Museum, September 10-11, 2025

Please join us for this year’s California Nursery Conference in Santa Paula! We have a whole day of informative talks planned, including a session bridging nursery and landscape interests, and there are many fabulous stops on the tour of local nurseries and greenhouses. The conference is coming right up from September 10-11, and discounted registration is open through the end of August. More information and registration here.

Solano County Water Agency QWEL Training

For those working or living in Solano, Yolo, or Napa Counties, Solano County Water Agency is offering a Qualified Water Efficient Landscaper (QWEL) training this fall. This is a free online certification that focuses on water efficient landscaping principles, taught by the fabulous Lori Palmquist. The training begins September 15th and runs through the 25th, with classes on Zoom from 8am-10:30 am. There is a $30 fee for the certifying exam. More information and registration here.

Watch out for invasive species!

Invasive species can cause extensive economic and ecological harm. Check out UC IPM’s list of invasive species to be on the watch for, including spotted lanternfly, and familiarize yourself with Asian jumping worms, which have been found in Sacramento. This entire bucket of jumping worms was gathered in one day from a small section of a garden in Massachusetts! Please reports sightings to your county’s Agricultural Commissioner.

From the Journals

A few recently published studies that might be of interest:

Observing anthropogenic and biogenic CO₂ emissions in Los Angeles using a dense sensor network

Trees and other vegetation in Los Angeles can consume a greater percentage of fossil fuel emissions than previously thought—up to 60% in the growing season during daytime hours. (This article gives a good summary.)

Artificial light at night outweighs temperature in lengthening urban growing seasons

In urban centers, artificial light at night is extending the growing season of plants and is more influential than the urban heat island effect.

Watching nature through the window cannot be overlooked!

More vegetation in a window view was associated with greater physical activity intensity in older adults.

Impact of air pollution on microbial communities on urban plant leaf surfaces

Particulate matter deposition on leaves influences microbial diversity and composition, likely altering the ecosystem services the leaf microbiome provides (e.g., degradation of airborne pollutants).

Visit the UCCE Capitol Corridor website