Forests

The golden flowers of French broom covering hillsides and the tall, striking stalks of pampasgrass stand out on trails and roadsides. These plants may be beautiful, but they are invasive and harm California’s natural landscapes.  Invasive plants outcompete and crowd out native plants, damaging…

While bringing firewood from home for your weekend camping trip may seem harmless, many invasive pests can hide in firewood and cause serious harm to California’s forests and urban landscapes. You can help limit the spread of these unwanted hitchhikers by collecting or buying firewood close to where you plan…

 Las copas de los árboles urbanos (UTC), es decir, las capas de hojas, ramas y tallos que cubren el suelo en las ciudades, son herramientas esenciales para gestionar las aguas pluviales, en particular en zonas urbanas densas como las del sur de California. En paisajes dominados por superficies…

The Mediterranean Oak Borer (MOB) is an invasive ambrosia beetle that infests several species of white oaks in California: valley oak, blue oak, and Oregon oak. The beetle is spreading rapidly in Northern California counties and there is considerable potential for the beetle's range to expand as they…

Urban tree canopies (UTCs), i.e, the layers of leaves, branches, and stems that cover the ground in cities, are essential tools in managing stormwater, particularly in dense urban areas like those across Southern California. In landscapes dominated by impermeable surfaces such as pavements and rooftops,…

General outlook & thrips populationAs planting wraps up, temperatures remain similar to long-term averages. Thrips population predictions are similar to last week’s update. Generation 2 adults peaked a couple weeks ago; generation three adults are predicted to peak 6/8.  The 3rd and 4th…

Tiny but destructive, the emerald ash borer (EAB) is an invasive beetle that has killed millions of ash trees across North America. In some cases, infested regions have lost nearly 100% of their ash trees to this pest. Though EAB has not yet been found in California, it was detected on the West Coast for the…

When you spot a plant in your garden that doesn’t look healthy, how do you figure out what’s wrong with it? Plant problems can be caused by insects, mites, vertebrates, environmental conditions, and diseases, but it can sometimes be hard to tell which is causing the problem. UC IPM's Plant Problem…